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Aims: \ud Identifying novel mediators of lethal myocardial reperfusion injury that can be targeted during primary percutaneous coronary intervention (PPCI) is key to limiting the progression of patients with ST-elevated myocardial infarction (STEMI) to heart failure. Here we show through parallel clinical and integrative preclinical studies the significance of the protease cathepsin-L on cardiac function during reperfusion injury.\ud \ud Methods and Results: \ud We found that direct cardiac release of cathepsin-L in STEMI patients (n = 76) immediately post-PPCI leads to elevated serum cathepsin-L levels and that serum levels of cathepsin-L in the first 24 hour post-reperfusion are associated with reduced cardiac contractile function and increased infarct size. Preclinical studies, demonstrate that inhibition of cathepsin-L release following reperfusion injury with CAA0225 reduces infarct size and improves cardiac contractile function by limiting abnormal cardiomyocyte calcium handling and apoptosis.\ud \ud Conclusion: \ud Our findings suggest that cathepsin-L is a novel therapeutic target that could be exploited clinically to counteract the deleterious effects of acute reperfusion injury after an acute STEMI.\ud \ud Translational perspective: \ud New therapeutic targets are urgently required to limit myocardial damage after reperfusion injury. We identified cardiac release of the protease cathepsin-L among patients following primary percutaneous coronary intervention (PPCI). Elevated serum levels of cathepsin-L were associated with reduced contractile function and increased infarct size at 24 hour and 6 months post-PPCI. Work conducted using animal models indicated that cardiac release of cathepsin-L mediated cardiac dysfunction following reperfusion injury. Specific inhibition of cathepsin-L prevented abnormal calcium handling, reduced infarct size and improved contractile function. These novel findings offer the prospect of targeting cathepsin-L-mediated cardiac dysfunction after PPCI.

Background Segmental extent of infarction assessed by late gadolinium enhancement (LGE) imaging early post‐ST‐segment elevation myocardial infarction (STEMI) has utility in predicting left ventricular functional recovery. Hypothesis: We hypothesized that segmental circumferential strain with displacement encoding with stimulated echoes (DENSE) would be a stronger predictor of infarct transmurality than feature‐tracking strain, and noninferior to extracellular volume fraction (ECV). Study Type: Prospective. Population: Fifty participants (mean ± SD, 59 ± 9 years, 40 [80%] male) underwent cardiac MRI on day 1 post‐STEMI. Field‐Strength/Sequences: 1.5T/cine, DENSE , T1 mapping, ECV , LGE. Assessment Two observers assessed segmental percentage LGE extent, presence of microvascular obstruction (MVO), circumferential and radial strain with DENSE and feature‐tracking, T1 relaxation times, and ECV. Statistical Tests: Normality was tested using the Shapiro–Wilk test. Skewed distributions were analyzed utilizing Mann–Whitney or Kruskal–Wallis tests and normal distributed data using independent t ‐tests. Diagnostic cutoff values were identified using the Youden index. The difference in area under the curve was compared using the z‐statistic. Results: Segmental circumferential strain with DENSE was associated with the extent of infarction ≥50% (AUC [95% CI], cutoff value = 0.9 [0.8, 0.9], −10%) similar to ECV (AUC = 0.8 [0.8, 0.9], 37%) (P = 0.117) and superior to feature‐tracking circumferential strain (AUC = 0.7[0.7, 0.8], −19%) (P

IntroductionThere is conflicting evidence regarding the benefits of percutaneous coronary intervention (PCI) in patients with grey zone fractional flow reserve (GZFFR artery) values (0.75–0.80). The prevalence of ischaemia is unknown. We wished to define the prevalence of ischaemia inGZFFR artery and assess whether PCI is superior to optimal medical therapy (OMT) for angina control.MethodsWe enrolled 104 patients with angina with 1:1 randomisation to PCI or OMT. The artery was interrogated with a Doppler flow/pressure wire. Patients underwent Magnetic Resonance Imaging (MRI) with follow-up at 3 and 12 months. The primary outcome was angina status at 3 months using the Seattle Angina Questionnaire (SAQ).Results104 patients (age 60±9 years), 79 (76%) males and 79 (76%) Left Anterior Descending (LAD) stenoses were randomised. Coronary physiology and SAQ were similar. Of 98 patients with stress perfusion MRI data, 17 (17%) had abnormal perfusion (≥2 segments with ≥25% ischaemia or ≥1 segment with ≥50% ischaemia) in the targetGZFFR artery. Of 89 patients with invasive physiology data, 26 (28%) had coronary flow velocity reserve GZFFR artery. After 3 months of follow-up, compared with patients treated with OMT only, patients treated by PCI and OMT had greater improvements in SAQ angina frequency (21 (28) vs 10 (23); p=0.026) and quality of life (24 (26) vs 11 (24); p=0.008) though these differences were no longer significant at 12 months.ConclusionsNon-invasive evidence of major ischaemia is uncommon in patients withGZFFR artery. Compared with OMT alone, patients randomised to undergo PCI reported improved symptoms after 3 months but these differences were no longer significant after 12 months.Trial registration numberNCT02425969.

Objectives The aim of this study was to test the hypothesis that invasive coronary function testing at time of angiography could help stratify management of angina patients without obstructive coronary artery disease. Background Medical therapy for angina guided by invasive coronary vascular function testing holds promise, but the longer-term effects on quality of life and clinical events are unknown among patients without obstructive disease. Methods A total of 151 patients with angina with symptoms and/or signs of ischemia and no obstructive coronary artery disease were randomized to stratified medical therapy guided by an interventional diagnostic procedure versus standard care (control group with blinded interventional diagnostic procedure results). The interventional diagnostic procedure–facilitated diagnosis (microvascular angina, vasospastic angina, both, or neither) was linked to guideline-based management. Pre-specified endpoints included 1-year patient-reported outcome measures (Seattle Angina Questionnaire, quality of life [EQ-5D]) and major adverse cardiac events (all-cause mortality, myocardial infarction, unstable angina hospitalization or revascularization, heart failure hospitalization, and cerebrovascular event) at subsequent follow-up. Results Between November 2016 and December 2017, 151 patients with ischemia and no obstructive coronary artery disease were randomized (n = 75 to the intervention group, n = 76 to the control group). At 1 year, overall angina (Seattle Angina Questionnaire summary score) improved in the intervention group by 27% (difference 13.6 units; 95% confidence interval: 7.3 to 19.9; p, Central Illustration

BackgroundCoronary artery bypass graft (CABG) patients are under-represented in acute coronary syndrome (ACS) trials. We compared characteristics and outcomes for patients who did and did not participate in a randomised trial of invasive versus non-invasive management (CABG-ACS).MethodsACS patients with prior CABG in four hospitals were randomised to invasive or non-invasive management. Non-randomised patients entered a registry. Primary efficacy (composite of all-cause mortality, rehospitalisation for refractory ischaemia/angina, myocardial infarction (MI), heart failure) and safety outcomes (composite of bleeding, stroke, procedure-related MI, worsening renal function) were independently adjudicated.ResultsOf 217 patients screened, 84 (39%) screenfailed, of whom 24 (29%) did not consent and 60 (71%) were ineligible. Of 133 (61%) eligible, 60 (mean±SD age, 71±9 years, 72% male) entered the trial and 73 (age, 72±10 years, 73% male) entered a registry (preferences: physician (79%), patient (38%), both (21%)).Compared with trial participants, registry patients had more valve disease, lower haemoglobin, worse New York Heart Association class and higher frailty.At baseline, invasive management was performed in 52% and 49% trial and registry patients, respectively, of whom 32% and 36% had percutaneous coronary intervention at baseline, respectively (p=0.800). After 2 years follow-up (694 (median, IQR 558–841) days), primary efficacy (43% trial vs 49% registry (HR 1.14, 95% CI 0.69 to 1.89)) and safety outcomes (28% trial vs 22% registry (HR 0.74, 95% CI 0.37 to 1.46)) were similar. EuroQol was lower in registry patients at 1 year.ConclusionsCompared with trial participants, registry participants had excess morbidity, but longer-term outcomes were similar.Trial registration numberNCT01895751.

Aims A fractional flow reserve (FFR) value ≥0.90 after percutaneous coronary intervention (PCI) is associated with a reduced risk of adverse cardiovascular events. TARGET-FFR is an investigator-initiated, single-centre, randomized controlled trial to determine the feasibility and efficacy of a post-PCI FFR-guided optimization strategy vs. standard coronary angiography in achieving final post-PCI FFR values ≥0.90. Methods and results After angiographically guided PCI, patients were randomized 1:1 to receive a physiology-guided incremental optimization strategy (PIOS) or a blinded coronary physiology assessment (control group). The primary outcome was the proportion of patients with a final post-PCI FFR ≥0.90. Final FFR ≤0.80 was a prioritized secondary outcome. A total of 260 patients were randomized (131 to PIOS, 129 to control) and 68.1% of patients had an initial post-PCI FFR Conclusion Over two-thirds of patients had a physiologically suboptimal result after angiography-guided PCI. An FFR-guided optimization strategy did not significantly increase the proportion of patients with a final FFR ≥0.90, but did reduce the proportion of patients with a final FFR ≤0.80.

Background: Patients with angina symptoms and/or signs of ischemia but no obstructive coronary artery disease (INOCA) pose a diagnostic and therapeutic challenge.Objectives: The purpose of ...

Aim Coronary angiography is indicated in many patients with known or suspected angina for the investigation of coronary artery disease (CAD). However, up to half of patients with symptoms of ischaemia have no obstructive coronary arteries (INOCA). This large subgroup includes patients with suspected microvascular angina (MVA) and/or vasospastic angina (VSA). Clinical guidelines relating to the management of patients with INOCA are limited. Uncertainty regarding the diagnosis of patients with INOCA presents a health economic challenge, both in terms of healthcare resource utilisation and of quality-of-life impact on patients. Methods A cost-effectiveness analysis of the introduction of stratified medicine into the invasive management of INOCA, based on clinical and resource-use data obtained in the CorMicA trial, from a UK NHS perspective. The intervention included an invasive diagnostic procedure (IDP) of coronary vascular function during coronary angiography to define clinical endotypes to target with linked medical therapy. Outcomes of interest were mean total cost and QALY gain between treatment groups, and the incremental cost-effectiveness ratio. We undertook probabilistic sensitivity and scenario analyses. Results The incremental cost per QALY gained at 12 months was £4500 (£2937, £33264). Compared with a willingness-to-pay (WTP) threshold of £20,000 per QALY, the use of the IDP test is cost-effective. At this WTP threshold there is a 96% probability of the IDP being cost-effective, based on the uncertainty described by bootstrap analysis. Conclusions The burden of INOCA, particularly in women, is known to be significant. These findings provided new evidence to inform this unmet clinical need.

Background: The index of microcirculatory resistance (IMR) of the infarct-related artery and left ventricular end-diastolic pressure (LVEDP) are acute, prognostic biomarkers in patients undergoing primary percutaneous coronary intervention. The clinical significance of IMR and LVEDP in combination is unknown. Methods: IMR and LVEDP were prospectively measured in a prespecified substudy of the T-TIME clinical trial (Trial of Low Dose Adjunctive Alteplase During Primary PCI). IMR was measured using a pressure- and temperature-sensing guidewire following percutaneous coronary intervention. Prognostically established thresholds for IMR (>32) and LVEDP (>18 mm Hg) were predefined. Contrast-enhanced cardiovascular magnetic resonance imaging (1.5 Tesla) was acquired 2 to 7 days and 3 months postmyocardial infarction. The primary end point was major adverse cardiac events, defined as cardiac death/nonfatal myocardial infarction/heart failure hospitalization at 1 year. Results: IMR and LVEDP were both measured in 131 patients (mean age 59±10.7 years, 103 [78.6%] male, 48 [36.6%] with anterior myocardial infarction). The median IMR was 29 (interquartile range, 17–55), the median LVEDP was 17 mm Hg (interquartile range, 12–21), and the correlation between them was not statistically significant ( r =0.15; P =0.087). Fifty-three patients (40%) had low IMR (≤32) and low LVEDP (≤18), 18 (14%) had low IMR and high LVEDP, 31 (24%) had high IMR and low LVEDP, while 29 (22%) had high IMR and high LVEDP. Infarct size (% LV mass), LV ejection fraction, final myocardial perfusion grade ≤1, TIMI (Thrombolysis In Myocardial Infarction) flow grade ≤2, and coronary flow reserve were associated with LVEDP/IMR group, as was hospitalization for heart failure (n=18 events; P =0.045) and major adverse cardiac events (n=21 events; P =0.051). LVEDP>18 and IMR>32 combined was associated with major adverse cardiac events, independent of age, estimated glomerular filtration rate, and infarct-related artery (odds ratio, 5.80 [95% CI, 1.60–21.22] P =0.008). The net reclassification improvement for detecting major adverse cardiac events was 50.6% (95% CI, 2.7–98.2; P =0.033) when LVEDP>18 was added to IMR>32. Conclusions: IMR and LVEDP in combination have incremental value for risk stratification following primary percutaneous coronary intervention. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02257294.

Background Angina is associated with impaired quality of life and an adverse prognosis. Purpose Prospectively evaluate quality of life and clinical outcomes in patients with angina undergoing invasive coronary angiography according to endotype: symptoms and/or signs of ischaemia and no obstructive coronary artery disease (INOCA) compared to obstructive coronary artery disease subjects managed by medical therapy, revascularization with percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery, respectively. Methods We conducted a prospective clinical evaluation of patients with angina undergoing clinically indicated invasive management (NCT03193294). Symptom severity and quality of life were assessed at baseline and repeated after 6 months. Comparisons between treatment groups were based on analysis of covariance general linear models adjusting for baseline score, sex, and cardiovascular risk. INOCA subjects were considered as one diagnostic group and not all subjects had invasive vasoreactivity testing. Results 391 patients (mean age 62±10 years, 52% female) were enrolled over 12 months and classified into one of four groups: INOCA (N=185; 47%), obstructive CAD treated by PCI (N=126; 32%), obstructive CAD treated by CABG (N=48; 12%) and obstructive CAD managed with medical therapy (N=32; 8%). After adjusting for between group differences and overall risk, INOCA subjects had worse angina and worse treatment response at follow up (21% and 27% reduction in angina score compared to CAD patients revascularized with PCI and CABG respectively). INOCA subjects had numerically lower treatment response than CAD patients managed with medications (6.4 units, −12%; P=0.181). Population baseline mean Seattle Angina Questionnaire (SAQ) frequency score (60±26) and SAQ summary score (52.5±19) were similar between groups. The absolute difference was 6.4 units versus medically managed CAD (95% CI: −3.0 to 15.9; P=0.181), 11.3 units versus the CAD group undergoing PCI (6.1 to 16.5; P Conclusion(s) Patients with INOCA had more severe angina symptoms reflecting worse quality of life and treatment response at 6 months with similar MACE as CAD subjects even after adjustment for confounding factors. This study highlights the need for evidence-based antianginal therapies and disease-modifying treatments for angina patients regardless of the presence of obstructive coronary disease. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): This work was funded by the British Heart Foundation (PG/17/2532884; RE/13/5/30177; RE/18/6134217)

Background: Cut off values for change in left ventricular end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) by cardiovascular magnetic resonance following ST-segment–elevation myocardial infarction have recently been proposed and 4 patterns of LV remodeling were described. We aimed to assess their long-term prognostic significance. Methods: A prospective cohort of unselected patients with ST-segment–elevation myocardial infarction with paired acute and 6-month cardiovascular magnetic resonance, with the 5-year composite end point of all-cause death and hospitalization for heart failure was included. The prognosis of the following groups (group 1: reverse LV remodeling [≥12% decrease in LVESV]; group 2: no LV remodeling [changes in LVEDV and LVESV Results: Two hundred eighty-five patients were included with a median follow-up was 5.8 years. The composite end point occurred in 9.5% in group 1, 12.3% in group 2, 7.1% in group 3, and 24.2% in group 4. Group 4 had significantly higher cumulative event rates of the composite end point (log-rank test, P =0.03) with the other 3 groups showing similar cumulative event rates (log-rank test, P =0.51). Cox proportional hazard for group 2 (hazard ratio, 1.3 [95% CI, 0.6–3.1], P =0.53) and group 3 (hazard ratio, 0.6 [95% CI, 0.2–2.3], P =0.49) were not significantly different but was significantly higher in group 4 (hazard ratio, 3.0 [95% CI, 1.2–7.1], P =0.015) when compared with group 1. Conclusions: Patients with ST-segment–elevation myocardial infarction developing adverse LV remodeling at 6 months, defined as ≥12% increase in both LVESV and LVEDV by cardiovascular magnetic resonance, was associated with worse long-term clinical outcomes than those with adverse LV remodeling with compensation, reverse LV remodeling, and no LV remodeling, with the latter 3 groups having similar outcomes in a cohort of stable reperfused patients with ST-segment–elevation myocardial infarction. Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT02072850.

Aims Endothelin-1 (ET-1) is a potent vasoconstrictor peptide linked to vascular diseases through a common intronic gene enhancer [(rs9349379-G allele), chromosome 6 (PHACTR1/EDN1)]. We performed a multimodality investigation into the role of ET-1 and this gene variant in the pathogenesis of coronary microvascular dysfunction (CMD) in patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (CAD). Methods and results Three hundred and ninety-one patients with angina were enrolled. Of these, 206 (53%) with obstructive CAD were excluded leaving 185 (47%) eligible. One hundred and nine (72%) of 151 subjects who underwent invasive testing had objective evidence of CMD (COVADIS criteria). rs9349379-G allele frequency was greater than in contemporary reference genome bank control subjects [allele frequency 46% (129/280 alleles) vs. 39% (5551/14380); P = 0.013]. The G allele was associated with higher plasma serum ET-1 [least squares mean 1.59 pg/mL vs. 1.28 pg/mL; 95% confidence interval (CI) 0.10–0.53; P = 0.005]. Patients with rs9349379-G allele had over double the odds of CMD [odds ratio (OR) 2.33, 95% CI 1.10–4.96; P = 0.027]. Multimodality non-invasive testing confirmed the G allele was associated with linked impairments in myocardial perfusion on stress cardiac magnetic resonance imaging at 1.5 T (N = 107; GG 56%, AG 43%, AA 31%, P = 0.042) and exercise testing (N = 87; −3.0 units in Duke Exercise Treadmill Score; −5.8 to −0.1; P = 0.045). Endothelin-1 related vascular mechanisms were assessed ex vivo using wire myography with endothelin A receptor (ETA) antagonists including zibotentan. Subjects with rs9349379-G allele had preserved peripheral small vessel reactivity to ET-1 with high affinity of ETA antagonists. Zibotentan reversed ET-1-induced vasoconstriction independently of G allele status. Conclusion We identify a novel genetic risk locus for CMD. These findings implicate ET-1 dysregulation and support the possibility of precision medicine using genetics to target oral ETA antagonist therapy in patients with microvascular angina. Trial registration ClinicalTrials.gov: NCT03193294.

Background Impaired microcirculatory reperfusion worsens prognosis following acute ST ‐segment–elevation myocardial infarction. In the T‐ TIME (A Trial of Low‐Dose Adjunctive Alteplase During Primary PCI) trial, microvascular obstruction on cardiovascular magnetic resonance imaging did not differ with adjunctive, low‐dose, intracoronary alteplase (10 or 20 mg) versus placebo during primary percutaneous coronary intervention. We evaluated the effects of intracoronary alteplase, during primary percutaneous coronary intervention, on the index of microcirculatory resistance, coronary flow reserve, and resistive reserve ratio. Methods and Results A prespecified physiology substudy of the T‐ TIME trial. From 2016 to 2017, patients with ST ‐segment–elevation myocardial infarction ≤6 hours from symptom onset were randomized in a double‐blind study to receive alteplase 20 mg, alteplase 10 mg, or placebo infused into the culprit artery postreperfusion, but prestenting. Index of microcirculatory resistance, coronary flow reserve, and resistive reserve ratio were measured after percutaneous coronary intervention. Cardiovascular magnetic resonance was performed at 2 to 7 days and 3 months. Analyses in relation to ischemic time (P =0.013), resistive reserve ratio ( P =0.026), and microvascular obstruction ( P =0.022), but not index of microcirculatory resistance. Conclusions In ST ‐segment–elevation myocardial infarction with ischemic time ≤6 hours, there was overall no difference in microvascular function with alteplase versus placebo. Clinical Trial Registration URL : https://www.clinicaltrials.gov . Unique identifier: NCT 02257294.

Supplemental Digital Content is available in the text., The rationale for our study was to investigate the pathophysiology of microvascular injury in patients with acute ST-segment–elevation myocardial infarction in relation to a history of hypertension. We undertook a cohort study using invasive and noninvasive measures of microvascular injury, cardiac magnetic resonance imaging at 2 days and 6 months, and assessed health outcomes in the longer term. Three hundred twenty-four patients with acute myocardial infarction (mean age, 59 [12] years; blood pressure, 135 [25] / 79 [14] mm Hg; 237 [73%] male, 105 [32%] with antecedent hypertension) were prospectively enrolled during emergency percutaneous coronary intervention. Compared with patients without antecedent hypertension, patients with hypertension were older (63 [12] years versus 57 [11] years; P

Supplemental Digital Content is available in the text., Background: Determine the prevalence and correlates of microvascular and vasospastic angina in patients with symptoms and signs of ischemia but no obstructive coronary artery disease (INOCA). Methods: Three hundred ninety-one patients with angina were enrolled at 2 regional centers over 12 months from November 2016 (NCT03193294). INOCA subjects (n=185; 47%) had more limiting dyspnea (New York Heart Association classification III/IV 54% versus 37%; odds ratio [OR], 2.0 [1.3–3.0]; P=0.001) and were more likely to be female (68% INOCA versus 38% in coronary artery disease; OR, 1.9 [1.5 to 2.5]; P

Background: The benefits of routine invasive management in patients with prior coronary artery bypass grafts presenting with non-ST elevation acute coronary syndromes are uncertain because these patients were excluded from pivotal trials. Methods: In a multicenter trial, non-ST elevation acute coronary syndromes patients with prior coronary artery bypass graft were prospectively screened in 4 acute hospitals. Medically stabilized patients were randomized to invasive management (invasive group) or noninvasive management (medical group). The primary outcome was adherence with the randomized strategy by 30 days. A blinded, independent Clinical Event Committee adjudicated predefined composite outcomes for efficacy (all-cause mortality, rehospitalization for refractory ischemia/angina, myocardial infarction, hospitalization because of heart failure) and safety (major bleeding, stroke, procedure-related myocardial infarction, and worsening renal function). Results: Two hundred seventeen patients were screened and 60 (mean±SD age, 71±9 years, 72% male) were randomized (invasive group, n=31; medical group, n=29). One-third (n=10) of the participants in the invasive group initially received percutaneous coronary intervention. In the medical group, 1 participant crossed over to invasive management on day 30 but percutaneous coronary intervention was not performed. During 2-years’ follow-up (median [interquartile range], 744 [570–853] days), the composite outcome for efficacy occurred in 13 (42%) subjects in the invasive group and 13 (45%) subjects in the medical group. The composite safety outcome occurred in 8 (26%) subjects in the invasive group and 9 (31%) subjects in the medical group. An efficacy or safety outcome occurred in 17 (55%) subjects in the invasive group and 16 (55%) subjects in the medical group. Health status (EuroQol 5 Dimensions) and angina class in each group were similar at 12 months. Conclusions: More than half of the population experienced a serious adverse event. An initial noninvasive management strategy is feasible. A substantive health outcomes trial of invasive versus noninvasive management in non-ST elevation acute coronary syndromes patients with prior coronary artery bypass grafts appears warranted. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01895751.

Background Ischemia and no obstructive epicardial coronary artery disease (INOCA) is a common clinical syndrome with distinct underlying causes. Objective To evaluate the prevalence and predictors of microvascular and/or vasospastic angina (MVA/VSA) in an unselected cohort of angina patients referred for invasive coronary angiography with suspected ischaemic heart disease in whom obstructive coronary artery disease (CAD) is excluded. Methods Prospective cohort study at two regional centres between November 2016 and December 2017 including patients with symptoms and/or signs of ischaemia prior to undergoing invasive coronary angiography (NCT03193294). Baseline risk was assessed (ASSIGN score) and validated questionnaires were completed prior to the angiogram including Rose angina, quality of life (EuroQOL [EQ-5D-5L]) and angina severity according to the Seattle Angina Questionnaire (SAQ). Patients with definite or probable angina without CAD [diameter stenosis 0.80] proceeded directly to assessment for disorders of coronary vasomotion. This involved an ad hoc interventional diagnostic procedure (IDP) using reference invasive tests for microvascular angina (MVA), vasospastic angina (VSA), both conditions or none. MVA and VSA groups were compared before logistic regression was performed to assess predictors of MVA and VSA. Results Three hundred and ninety-one patients with angina were recruited before undergoing invasive coronary angiography during the study period. Overall, 185 (47%) of subjects had INOCA and 151 of these underwent an IDP. INOCA patients reported similar angina burden with worse quality of life than CAD subjects (EQ5D-5L index 0.60 v 0.65 units; P=0.041). The mean age of patients who underwent the IDP was 60.9 years, 74% were female and their median predicted 10-year IHD risk was 18.6% (10.6, 31.4). 78 subjects (52%) had isolated microvascular angina, 25 (17%) had isolated vasospastic angina, 31 (20%) had both (MVA & VSA) only 17 (11%) had non-cardiac chest pain. Myocardial bridging of coronary artery was found in 22 (15%). Multivariate predictors of MVA included typical angina, inducible ischaemia but traditional cardiovascular risk factors were not associated. Smoking and age were independent predictors of VSA. Conclusion The majority of patients with symptoms and/or signs of ischemia and no obstructive disease have a diagnosis of microvascular and/or vasospastic angina. Traditional cardiovascular risk scores have limited discrimination for disorders of coronary vasomotion. Conflict of Interest Nil

Background Invasive measures of microvascular resistance in the culprit coronary artery have potential for risk stratification in acute ST‐segment–elevation myocardial infarction. We aimed to investigate the pathological and prognostic significance of coronary thermodilution waveforms using a diagnostic guidewire. Methods and Results Coronary thermodilution was measured at the end of percutaneous coronary intervention, (PCI) and contrast‐enhanced cardiac magnetic resonance imaging (MRI) was intended on day 2 and 6 months later to assess left ventricular (LV) function and pathology. All‐cause death or first heart failure hospitalization was a pre‐specified outcome (median follow‐up duration 1469 days). Thermodilution recordings underwent core laboratory assessment. A total of 278 patients with acute ST‐segment elevation myocardial infarction EMI (72% male, 59±11 years) had coronary thermodilution measurements classified as narrow unimodal (n=143 [51%]), wide unimodal (n=100 [36%]), or bimodal (n=35 [13%]). Microvascular obstruction and myocardial hemorrhage were associated with the thermodilution waveform pattern ( P =0.007 and 0.011, respectively), and both pathologies were more prevalent in patients with a bimodal morphology. On multivariate analysis with baseline characteristics, thermodilution waveform status was a multivariable associate of microvascular obstruction (odds ratio [95% confidence interval]=5.29 [1.73, 16.22];, P =0.004) and myocardial hemorrhage (3.45 [1.16, 10.26]; P =0.026), but the relationship was not significant when index of microvascular resistance (IMR) >40 or change in index of microvascular resistance (5 per unit) was included. However, a bimodal thermodilution waveform was independently associated with all‐cause death and hospitalization for heart failure (odds ratio [95% confidence interval]=2.70 [1.10, 6.63]; P =0.031), independent of index of microvascular resistance>40, ST‐segment resolution, and TIMI (Thrombolysis in Myocardial Infarction) Myocardial Perfusion Grade. Conclusions The thermodilution waveform in the culprit coronary artery is a biomarker of prognosis and may be useful for risk stratification immediately after reperfusion therapy.

Background There is an evidence-gap about how to best treat patients with a history of prior CABG presenting with a NSTE-ACS because these patients were excluded from key randomised trials. Methods The CABG-ACS pilot trial (NCT01895751) randomised patients with a NSTE-ACS and prior CABG to routine invasive or non-invasive management. The primary efficacy outcome was a composite of all-cause death, rehospitalisation for refractory ischaemia/angina, MI and HF hospitalisation. The primary safety outcome was a composite of bleeding, stroke, procedure-related MI and worsening renal function. A CEC assessed events. Results 60 patients (mean ±SD age 71±9 years, 28% female) were randomised to invasive (n=31) or non-invasive (n=29) management. The invasive group had worse NYHA class (p=0.044) and less valve disease (17% vs 27%; p=0.035). Other comorbidities, age, sex, CCS grade, frailty score and medications were similar. Baseline LIMA grafts were similar (p=0.720). All invasive group patients had invasive management (mean BCIS-1 Jeopardy Score 7±4) and 6 (19%) had PCI. 6 non-invasive group patients ended up having invasive management and 3 (50%) had PCI. No patients had redo CABG. The primary efficacy outcome occurred in 42% invasive vs 45% non-invasive groups (RR (95% CI) 0.94 (0.52, 1.67); p=1.000). The primary safety outcome occurred in 26% invasive vs 31% non-invasive groups (RR 0.83 (0.37, 1.86); p=0.777). EQ-5D was similar at 1 year. Conclusion Compared with routine non-invasive management, a strategy of routine invasive management was not associated with patient benefits.

Background— Distal coronary to aortic pressure ratio (Pd/Pa) and instantaneous wave-free ratio (iFR) are indices of functional significance of a coronary stenosis measured without hyperemia. It has been suggested that iFR has superior diagnostic accuracy to Pd/Pa when compared with fractional flow reserve (FFR). We hypothesized that in comparison with FFR, revascularization decisions based on either binary cutoff values for iFR and Pd/Pa or hybrid strategies incorporating iFR or Pd/Pa will result in similar levels of disagreement. Methods and Results— This is a prospective study in consecutive patients undergoing FFR for clinical indications using proprietary software to calculate iFR. We measured Pd/Pa, iFR, FFR, and hyperemic iFR. Diagnostic accuracy versus FFR ≤0.80 was calculated using binary cutoff values of ≤0.90 for iFR and ≤0.92 for Pd/Pa, and adenosine zones for iFR of 0.86 to 0.93 and Pd/Pa of 0.87 to 0.94 in the hybrid strategy. One hundred ninety-seven patients with 257 stenoses (mean diameter stenosis 48%) were studied. Using binary cutoffs, diagnostic accuracy was similar for iFR and resting Pd/Pa with misclassification rates of 21% versus 20.2% ( P =0.85). In the hybrid analysis, 54% of iFR cases and 53% of Pd/Pa cases were outside the adenosine zone and rates of misclassification were 9.4% versus 11.9% ( P =0.55). Conclusions— Binary cutoff values for iFR and Pd/Pa result in misclassification of 1 in 5 lesions. Using a hybrid strategy, approximately half of the patients do not receive adenosine, but 1 in 10 lesions are still misclassified. The use of nonhyperemic indices of stenosis severity cannot be recommended for decision making in the catheterization laboratory. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT02377310.

Introduction There is an evidence gap about how to best treat patients with prior coronary artery bypass grafts (CABGs) presenting with non-ST segment elevation acute coronary syndromes (NSTE-ACS) because historically, these patients were excluded from pivotal randomised trials. We aim to undertake a pilot trial of routine non-invasive management versus routine invasive management in patients with NSTE-ACS with prior CABG and optimal medical therapy during routine clinical care. Our trial is a proof-of-concept study for feasibility, safety, potential efficacy and health economic modelling. We hypothesise that a routine invasive approach in patients with NSTE-ACS with prior CABG is not superior to a non-invasive approach with optimal medical therapy. Methods and analysis 60 patients will be enrolled in a randomised clinical trial in 4 hospitals. A screening log will be prospectively completed. Patients not randomised due to lack of eligibility criteria and/or patient or physician preference and who give consent will be included in a registry. We will gather information about screening, enrolment, eligibility, randomisation, patient characteristics and adverse events (including post-discharge). The primary efficacy outcome is the composite of all-cause mortality, rehospitalisation for refractory ischaemia/angina, myocardial infarction and hospitalisation for heart failure. The primary safety outcome is the composite of bleeding, stroke, procedure-related myocardial infarction and worsening renal function. Health status will be assessed using EuroQol 5 Dimensions (EQ-5D) assessed at baseline and 6 monthly intervals, for at least 18 months. Trial registration number NCT01895751 (ClinicalTrials.gov).

Supplemental Digital Content is available in the text., The natural history and pathophysiological significance of tissue remodeling in the myocardial remote zone after acute ST-elevation myocardial infarction (STEMI) is incompletely understood. Extracellular volume (ECV) in myocardial regions of interest can now be measured with cardiac magnetic resonance imaging. Patients who sustained an acute STEMI were enrolled in a cohort study (BHF MR-MI [British Heart Foundation Magnetic Resonance Imaging in Acute ST-Segment Elevation Myocardial Infarction study]). Cardiac magnetic resonance was performed at 1.5 Tesla at 2 days and 6 months post STEMI. T1 modified Look-Locker inversion recovery mapping was performed before and 15 minutes after contrast (0.15 mmol/kg gadoterate meglumine) in 140 patients at 2 days post STEMI (mean age: 59 years, 76% male) and in 131 patients at 6 months post STEMI. Remote zone ECV was lower than infarct zone ECV (25.6±2.8% versus 51.4±8.9%; P

The index of microvascular resistance (IMR) is a direct, invasive test of coronary microvascular resistance [(1)][1]. When measured in the culprit coronary artery after emergency percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI), IMR is well established

Background: Elderly patients with multi-morbidity are often under-represented in clinical trials. The CABG-ACS pilot trial (NCT01895751) prospectively assessed reasons for entering the trial or registry and subsequent outcomes. Methods: Patients with a non-ST segment elevation acute coronary syndrome (NSTE-ACS) and prior coronary artery bypass graft (CABG) admitted to 4 hospitals were randomized to invasive or non-invasive management. Non-randomized patients entered a follow-up registry. The primary efficacy outcome was a composite of all-cause death, rehospitalization for refractory ischemia/angina, myocardial infarction (MI) and hospitalization due to heart failure. The primary safety outcome was the composite of bleeding, stroke, procedure-related MI and worsening renal function. A blinded Clinical Event Committee independently assessed events. EuroQol-5 Dimensions (EQ-5D) was assessed at 6 monthly intervals for ≥18 months. Results: 217 patients with prior CABG and unplanned hospitalization for suspected ACS were screened. 84 subjects did not consent (≥1 reasons): 43 not NSTE-ACS, 35 unsuitable for invasive management, 9 refractory ischemia, 3 unable to consent. Of 133 eligible subjects, 60 (mean±SD age 71±9 years, 28% female) entered the trial and 73 (age 72±10 years, 27% female) entered the registry (preferences: physician 79%, patient 40% or both 18%). Compared to trial patients, registry patients had significantly more valve disease, lower hemoglobin, worse New York Heart Association class and higher frailty index. Baseline EQ-5D, medications and left internal mammary artery grafts were similar. Registry patients had significantly more medication changes due to recurrent angina and more urgent inpatient invasive procedures. The primary efficacy outcome occurred in 49% registry vs. 43% trial patients (HR (95% CI) 1.12 (0.77,1.63); p=0.601). Primary safety outcomes were similar (22% registry vs. 28% trial; HR 0.76 (0.42,1.38); p=0.425). EQ-5D health status was lower in the registry at 6 months (p=0.011) but not at 1 year (p=0.068). Conclusion: Compared to trial patients, the registry had excess morbidity but their longer term health outcomes were similar.

The significance of remote myocardium in the natural history of STEMI is uncertain. Cardiac magnetic resonance (CMR) depicts left ventricular (LV) dimension and pathology. Native T1 quantified by CMR (T1 proton relaxation time, milliseconds) is a fundamental tissue property determined by water

Background: Myocardial longitudinal relaxation time (T1, ms) is a fundamental magnetic property of tissue that is related to water content and mobility. The pathophysiological and prognostic importance of native myocardial T1 values in acute STEMI patients is unknown. We aimed to assess the clinical significance of infarct tissue characteristics using native T1 cardiac magnetic resonance (CMR).\ud \ud Methods: We performed a prospective single center cohort study in reperfused STEMI patients who underwent CMR 2 days and 6 months post-MI. Native T1 CMR (MOLLI investigational prototype sequence: 3 (3) 3 (3) 5) was measured in myocardial regions-of-interest. The area-at-risk and infarct territory were depicted with T1 mapping and late gadolinium contrast enhancement imaging, respectively. All-cause death or heart failure hospitalization was a pre-specified outcome that was assessed during follow-up.\ud \ud Results: 300 STEMI patients (mean±SD age 59±12 years, 74% male, 114 with anterior STEMI) gave informed consent and had CMR (14 July 2011 - 22 November 2012). Of these, 288 STEMI patients had evaluable T1 maps and follow-up assessments (median duration 845 days). Infarct size was 18 ±14% of left ventricular mass. Microvascular obstruction occurred in 160 (55.6%) patients. Native T1 within the area-at-risk (1097 ±52 ms) was higher than in the remote zone (961 ±25 ms; p

Background:\ud Myocardial longitudinal relaxation time (T1, ms) is a fundamental magnetic property of tissue that is related to water content and mobility. The pathophysiological and prognostic importance of native myocardial T1 values in acute ST-elevation myocardial infarction (STEMI) patients is unknown. We aimed to assess the clinical significance of infarct core native T1.\ud Methods:\ud We performed a prospective single center cohort study in reperfused STEMI patients who underwent CMR 2 days and 6 months post-MI. Native T1 CMR (MOLLI investigational prototype sequence: 3 (3) 3 (3) 5) was measured in myocardial regions-of-interest. The infarct territory and microvascular obstruction (MVO) were depicted with late gadolinium enhancement CMR. Adverse remodeling was defined as an increase in LV end-diastolic volume (LVEDV) ≥ 20% at 6 months. All-cause death or heart failure hospitalization was a pre-specified outcome that was assessed during follow-up.\ud \ud Results:\ud 300 STEMI patients (mean±SD age 59±12 years, 74% male, 114 with anterior STEMI) gave informed consent and had CMR (14 July 2011 - 22 November 2012). Of these, 288 STEMI patients had evaluable T1 maps. Infarct size was 18 ±14% of LV mass. One hundred and forty five (50%) of 288 patients had late MVO, whereas 160 (56%) patients had infarct core pathology revealed by native T1. Native T1 within the infarct core (996.9±57.3; p

The orally administered PDE-5 inhibitors have become first-line treatment for erectile dysfunction. Although the three currently available PDE-5 inhibitors have shown similar efficacy, tadalafil has a much longer half-life than sildenafil or vardenafil, and the pharmacokinetic profile of tadalafil is not affected by food. However, there is a more immediate response to dosing with sildenafil and vardenafil than tadalafil. As with all drugs, there will be individual variations in response and the physician's skill is in finding the right drug for the right patient.

Erectile dysfunction is a distressing condition that may result from organic or psychological causes. Organic ED results from neurological, hormonal or vascular pathologies, and may also have drug-related causes. Cardiovascular disease and diabetes are the most common vascular risk factors. Due to a reluctance of patients to mention ED, healthcare professionals should discuss sexual dysfunction with patients who have increased risk of ED. This article considers underlying aetiologies and outlines treatment options.

Background: The pathophysiological basis of reperfusion injury in smokers is incompletely understood. Methods: Patients with acute STEMI were prospectively enrolled during emergency PCI, and categorized according to a current smoking status (yes/no). Contrast-enhanced MRI at 1.5T was acquired 2

Background: The segmental extent of late gadolinium enhancement imaged with cardiac magnetic resonance early after acute ST-segment elevation myocardial infarction (STEMI) has weak spatial correspondence with final infarct on follow-up, thus its prognostic value is uncertain. We hypothesized that

Objectives The aim of this study was to assess whether deferred stenting might reduce no-reflow and salvage myocardium in primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Background No-reflow is associated with adverse outcomes in STEMI. Methods This was a prospective, single-center, randomized, controlled, proof-of-concept trial in reperfused STEMI patients with ≥1 risk factors for no-reflow. Randomization was to deferred stenting with an intention-to-stent 4 to 16 h later or conventional treatment with immediate stenting. The primary outcome was the incidence of no-/slow-reflow (Thrombolysis In Myocardial Infarction ≤2). Cardiac magnetic resonance imaging was performed 2 days and 6 months after myocardial infarction. Myocardial salvage was the final infarct size indexed to the initial area at risk. Results Of 411 STEMI patients (March 11, 2012 to November 21, 2012), 101 patients (mean age, 60 years; 69% male) were randomized (52 to the deferred stenting group, 49 to the immediate stenting). The median (interquartile range [IQR]) time to the second procedure in the deferred stenting group was 9 h (IQR: 6 to 12 h). Fewer patients in the deferred stenting group had no-/slow-reflow (14 [29%] vs. 3 [6%]; p = 0.006), no reflow (7 [14%] vs. 1 [2%]; p = 0.052) and intraprocedural thrombotic events (16 [33%] vs. 5 [10%]; p = 0.010). Thrombolysis In Myocardial Infarction coronary flow grades at the end of PCI were higher in the deferred stenting group (p = 0.018). Recurrent STEMI occurred in 2 patients in the deferred stenting group before the second procedure. Myocardial salvage index at 6 months was greater in the deferred stenting group (68 [IQR: 54% to 82%] vs. 56 [IQR: 31% to 72%]; p = 0.031]. Conclusions In high-risk STEMI patients, deferred stenting in primary PCI reduced no-reflow and increased myocardial salvage. (Deferred Stent Trial in STEMI; NCT01717573 )

Aims This study assessed the use of systolic time intervals (STI) as a potential noninvasive marker of the haemodynamic eVects of sumatriptan, a 5HT1 receptor agonist. Methods Twenty-six patients undergoing diagnostic cardiac catheterization participated. STIs were derived from haemodynamic pressure tracings at baseline, following placebo injection and following either subcutaneous (n=18) or intravenous injection (n=8) of sumatriptan. Results Sumatriptan (i.v. or s.c.) was associated with significant increases in mean arterial pressure (95% C.I. 9,14mmHg, P=0.0001), total electromechanical systole (95% C.I.8,36ms, P

Background The clinical significance of infarct extracellular volume (ECV) post-STEMI is unknown. ECV can be estimated by cardiac magnetic resonance imaging (CMR) using T1 MOLLI maps. We measured infarct ECV in STEMI survivors, and assessed the relationships between ECV and markers of MI severity. Methods STEMI survivors were enrolled in a single-centre cohort study (BHF MR-MI study – NCT02072850). Culprit artery flow was described by thrombus in myocardial infarction (TIMI) classification. CMR was performed at 1.5 Tesla (Siemens MAGNETOM Avanto) 2-days and 6-months post-MI, including T1-mapping with MOLLI before and 15-minutes after contrast (0.15 mmol/kg gadoterate meglumine). ECV was analysed by outlining regions-of-interest (ROIs) in infarcted myocardium, including microvascular obstruction, and left ventricular (LV) blood pool. ECV was calculated as the relaxation rate (R1=1/T1) for myocardium and LV blood pool before vs. after contrast, corrected for haematocrit. ECV was compared with TIMI-flow pre- and post-percutaneous coronary intervention (PCI) and ST-segment resolution. A reduction in ST-segment voltage of ≥70% was considered complete ST-resolution and Results 201 STEMI patients (age 58 ± 11 years; 156 (77%) male) were enrolled. Infarct ECV was similar at baseline and follow-up (51.3 ± 9.5% vs. 50.3 ± 12.0%, p = 0.1). Pre-PCI, 131 (65%) patients had TIMI-flow 0 and 70 (35%) had TIMI-flow 1–3. Post-PCI, 3 (1.5%) patients had TIMI-flow 0 and 198 (98.5%) had TIMI-flow 2–3. TIMI-flow 0 pre-PCI was associated with higher infarct ECV at baseline (p Conclusion Preserved culprit artery flow and complete ST-resolution are associated with lower infarct ECV at baseline and follow-up. Clinical and electrocardiographic markers of MI severity are predictors of interstitial expansion in the infarct zone in STEMI patients.

Background Myocardial haemorrhage is a prognostically important complication of acute ST-elevation myocardial infarction (STEMI). Persistence of haemoglobin degradation products within infarct scar tissue and the potential clinical significance have not been investigated. Methods and Results Patients who sustained an acute STEMI were enrolled in a cohort study (BHF MR-MI; ClinicalTrials.gov: NCT02072850). 211 patients (mean (SD) age 57 (11) years, 77% male) had evaluable T2* cardiac magnetic resonance (CMR) imaging (1.5 Tesla) 2 days 6 months post-MI. Myocardial haemorrhage was defined as a hypointense infarct core with T2* signal de novo haemorrhage after the first CMR scan. Clinical associates of a persistent hypointense core at 6 months included hypertension (odds ratio (95% confidence interval) 0.28 (0.08, 0.95); p = 0.040), heart rate (1.08 (1.03, 1.13); p = 0.001), systolic blood pressure (1.06 (1.01, 1.12); p = 0.015), neutrophil count (2.19 (1.01, 4.74); p = 0.048), left anterior descending as culprit artery (9.26 (1.26, 67.99); p = 0.029), infarct size (1.10 (1.03, 1.17); p = 0.004) and initial haemorrhage size (1.34 (1.06, 1.66); p = 0.012). A hypointense infarct core with T2*-mapping at 6 months was associated with worsening LV end-diastolic volume (regression coefficient (95% confidence interval) 15.43 (1.35, 29.50); p = 0.032) and worsening left ventricular ejection fraction (-4.15 (-7.40, -0.89); p = 0.013). Conclusion Persistence of haemoglobin degradation products at 6 months post-STEMI is common and prognostically important.

Background The natural history of persistent myocardial oedema after ST-elevation myocardial infarction (STEMI) is uncertain. Methods and ResultsPatients who sustained an acute STEMI were enrolled in a cohort study (BHF MR-MI; ClinicalTrials.gov: NCT02072850). Cardiac magnetic resonance (CMR) imaging with T2-mapping of myocardial oedema was performed at 1.5 Tesla 2 days and 6 months post-MI. Myocardial oedema was defined as infarct signal intensity (S. I.) >2 standard deviations from the mean S. I. within a remote reference region. 283 STEMI patients (mean (SD) age 59 (12) years, 75% male) were enrolled. Infarct size was 18 (13)% of left ventricular (LV) mass. At 2 days, infarct zone T2 (ms) was higher than remote zone T2 (62.9 (5.2) vs. 49.7 (2.1); p Conclusion Persistence of oedema within the infarct zone affected the majority of patients at 6 months post-STEMI, and was associated with the initial severity of STEMI and adverse LV remodelling.

Distal coronary to aortic pressure ratio (Pd/Pa) and instantaneous wave-free ratio (iFR) are resting indices of the functional significance of a coronary stenosis measured without inducing hyperaemia. It has been suggested that iFR has superior diagnostic accuracy to Pd/Pa when both are compared to FFR. Hypotheses In comparison to an FFR for all strategy, revascularisation decisions based on either binary cut-off values for iFR or Pd/Pa or hybrid strategies incorporating iFR or Pd/Pa will result in similar levels of disagreement. Methods A prospective study in consecutive patients undergoing FFR assessment for clinical indications using proprietary software to calculate iFR. We measured Pd/Pa, iFR, FFR and hyperaemic iFR (HiFR). Diagnostic accuracy vs FFR was calculated firstly using binary cut-off values of Results 197 patients with 257 moderate stenoses (mean DS 48%) were studied. 127 (49.4%) vessels were in patients with stable angina and 79 (31%) vessels in patients with recent (>72 h) acute coronary syndromes. Using binary cut-off values diagnostic accuracy was similar for iFR and resting Pd/Pa with misclassification rates of 20.6% vs 19.8%, p = 0.86. In the hybrid analysis, 54% of iFR cases and 53% of Pd/Pa cases were outwith the adenosine zone. Rates of misclassification were 9.4% vs 11.9%, p = 0.55. Sensitivity analyses showed no impact of a variety of angiographic measures of stenosis severity or myocardial area at risk. Comparing proximal stenoses (Syntax segments 1, 11, 5 and 6) to all other lesions and using the RESOLVE cutoff of ≤0.90 for iFR the level of misclassification was 27.7% vs 15.2%, p = 0.014 (Table 1). Using the iFR cutoff of Conclusion When compared to FFR, binary cut-offs for iFR and Pd/Pa results in misclassification of 1 in 5 lesions. Using a hybrid strategy approximately half of the patient do not receive adenosine but 1 in 10 lesions is still misclassified. Neither resting index or strategy can be recommended for decision making in the cath lab. Operators wishing to use resting indices of stenosis severity should be particularly cautious when interpreting data from proximal stenoses in prognostically important vessels.

Background Despite the success of emergency PCI for acute STEMI, failed myocardial reperfusion (microvascular obstruction) is common and prognostically important, but it commonly passes undetected in clinical practice. Purpose To investigate coronary flow reserve (CFR) and the index of microvascular resistance (IMR) in the culprit coronary artery in patients with acute reperfused STEMI. Methods CFR and IMR were measured at the end of PCI using guidewire-based thermodilution (n = 283; mean age 60 (12) years, 73% male). CMR imaging was used to assess left ventricular (LV) function and infarct pathology 2 days and 6 months post-MI (n = 264). All-cause death or first heart failure hospitalisation (ACD) was a pre-specified outcome that was assessed during follow-up (median duration 845 days). Results The median [IQR] CFR was 1.6 [1.1–2.1] and the median IMR was 25 [15–48]. Microcirculatory status was associated with Killip Heart Failure classification, ST-segment resolution, LV ejection fraction and infarct size and pathology revealed by CMR 2 days later. In multivariate analysis, the combination of a CFR 25 was associated with changes in both LV ejection fraction (-2.47 (95% CI: -4.45, -0.49); p = 0.015) and LV end-diastolic volume (8.49 (1.96, 15.92); p = 0.025), and a CFR median was a multivariable (2.96 (1.24, 7.08); p = 0.015) associate of ACD. Conclusions The combination of a reduced CFR and an increased IMR immediately identifies patients who have a substantially increased risk of adverse LV outcomes and all-cause death or heart failure.

Despite the success of emergency percutaneous coronary intervention (PCI) for acute ST-elevation myocardial infarction (STEMI), failed myocardial reperfusion (microvascular obstruction (MVO)) is common and prognostically important. Our aim was to compare coronary flow reserve (CFR), a measure of

Background The pathophysiology of myocardial injury and repair in patients with ST‐elevation myocardial infarction is incompletely understood. We investigated the relationships among culprit artery microvascular resistance, myocardial salvage, and ventricular function. Methods and Results The index of microvascular resistance (IMR) was measured by means of a pressure‐ and temperature‐sensitive coronary guidewire in 108 patients with ST‐elevation myocardial infarction (83% male) at the end of primary percutaneous coronary intervention. Paired cardiac MRI (cardiac magnetic resonance) scans were performed early (2 days; n=108) and late (3 months; n=96) after myocardial infarction. T 2 ‐weighted‐ and late gadolinium–enhanced cardiac magnetic resonance delineated the ischemic area at risk and infarct size, respectively. Myocardial salvage was calculated by subtracting infarct size from area at risk. Univariable and multivariable models were constructed to determine the impact of IMR on cardiac magnetic resonance–derived surrogate outcomes. The median (interquartile range) IMR was 28 (17–42) mm Hg/s. The median (interquartile range) area at risk was 32% (24%–41%) of left ventricular mass, and the myocardial salvage index was 21% (11%–43%). IMR was a significant multivariable predictor of early myocardial salvage, with a multiplicative effect of 0.87 (95% confidence interval 0.82 to 0.92) per 20% increase in IMR; P P P Conclusion Microvascular resistance measured during primary percutaneous coronary intervention significantly predicts myocardial salvage, infarct characteristics, and left ventricular ejection fraction in patients with ST‐elevation myocardial infarction. ( J Am Heart Assoc . 2012;1:e002246 doi : 10.1161/JAHA.112.002246 )

Background The natural history and clinical significance of myocardial extracellular volume (ECV) in infarcted myocardium post-STEMI is uncertain. ECV can be estimated by cardiac magnetic resonance imaging (CMR). We measured infarct ECV of STEMI survivors, and assessed the relationships with clinical findings. Methods STEMI survivors were enrolled in a cohort study (BHF MR-MI study – NCT02072850). CMR was performed at 1.5 Tesla (Siemens MAGNETOM Avanto) 2 days and 6 months post-MI. T1 MOLLI mapping was performed pre- and 15 min post-contrast (0.15 mmol/kg gadoterate meglumin). ECV was calculated as the difference in relaxation rate (R1 = 1/T1) for myocardium and LV blood pool pre- vs. post-contrast, corrected for haematocrit (HCT). The percentage change in infarct ECV was calculated (%ΔECV). Results 129 patients (59 ± 11 years; 98 (76%) male) were included. Infarct ECV at baseline and follow-up was similar (49.5(9.3)% vs. 49.4 ± = (10.9)%; p = 0.904). The within-subject change in ECV varied markedly (1.0% (20.0%)). In multiple linear regression, TIMI coronary flow grade 2 pre-PCI, TIMI coronary flow grade 3 pre-PCI, a history of previous PCI and initial infarct size were independently associated with%ΔECV (all p Conclusion %ΔECV is associated with measures of MI severity, and portends worsening LV volume. Infarct ECV represents a novel biomarker for infarct characterisation in STEMI patients.