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Our study aimed to elucidate mechanisms underlying discordance between fractional flow reserve (FFR) and hyperemic stenosis resistance (hSR) in some patient subsets. To do this, we enrolled 30 consecutive patients with stable angina or noneST elevation myocardial infarction (non-STEMI) and with a nonculprit intermediate coronary lesion (40% to 70%) by coronary angiography. We measured aortic pressure, flow velocity, and pressure distal to lesion simultaneously at basal level and during adenosine-induced (fixed intracoronary dose of 120 mg) hyperemia using a dual-sensoreequipped guidewire. Microvascular resistance (MR; pressure distal to lesion/flow velocity, mm Hg/cm/s) and variation (Δ) in MR levels were calculated both at baseline and after hyperemia, whereas FFR (cutoff <0.80) and hSR [(aortic pressure L pressure distal to lesion)/flow velocity, cutoff >0.80 mm Hg/cm/s] were assessed after intracoronary adenosine. Twenty-three patients (76.7%) showed concordance and 7 patients (23.3%) showed discordance between FFR and hSR (all cases with FFR >0.80 and hSR >0.80). Discordant patients presented more frequently with non-STEMI (85.7% vs 39.1%, p [ 0.04), significantly higher C-reactive protein serum levels (median [interquartile range] 5.9 [5.1 to 6.8] vs 4.9 [3.7 to 6.2] mg/L, p[0.007), and lower ΔMR (p[ 0.03) values compared with concordant patients. In conclusion, patients with non-STEMI and those with increased C-reactive protein levels show a lower reduction in MR after intracoronary adenosineeinduced hyperemia, leading to FFR underestimation. [ABSTRACT FROM AUTHOR]

Abstract: Background: Systemic inflammation is involved in several pathological cardiovascular processes. However, whether it plays a role in the no-reflow phenomenon occurring in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI) is unknown. Methods: We studies 60 consecutive patients (59.5±12 years, 82% males) with a first ST-segment elevation AMI, treated by primary or rescue PCI within 6 h of symptom onset. Angiographic indexes of no-reflow, evaluated at the end of the procedure, included coronary TIMI flow grading, corrected TIMI frame count (c-TFC) and myocardial blush grade (MBG). ECG indexes of no-reflow included the lack of ST segment resolution (defined as a reduction <50% of the measured ST-segment elevation at 90 min, compared to the admission ECG), as analyzed both in the single lead with the maximal ST elevation and in all leads showing ST elevation on admission. Patients were divided into two groups according to baseline high-sensitivity C-reactive protein (CRP) serum levels measured on admission: high CRP group (CRP>5 mg/L) and low CRP group (CRP<5 mg/L). Results: A similar prevalence of final TIMI flow<3 and MBG<3 was observed in patients with high and low CRP serum levels (30% vs. 12%, p =0.1, and 50% vs. 53%, p =1.0, respectively), and c-TFC was also similar in the two groups (26±4.5 vs. 24±6, p =0.5). Accordingly, the prevalence of lack of ST-segment resolution in the two groups was similar, both by the single-lead method (25% vs. 25%, p =1.0) and the multiple-lead method (29% vs. 19%, p =0.4). Conclusion: In this study we failed to demonstrate any significant association between CRP serum levels on admission and coronary no-reflow, as assessed by both angiographic and ECG parameters in AMI patients treated by successful primary or rescue PCI within 6 h of chest pain onset. [Copyright &y& Elsevier]