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Background Microvascular dysfunction in the setting of ST-segment myocardial infarction (STEMI) is thought to be related to stress-related metabolic changes, including acute glucose intolerance. The aim of this study was to assess the relationship between admission glucose levels and microvascular function in non-diabetic STEMI patients. Methods 92 consecutive patients with a first anterior-wall STEMI treated with primary percutaneous coronary intervention (PPCI) were enrolled. Blood glucose levels were determined immediately prior to PPCI. After successful PPCI, at 1‑week and 6‑month follow-up, Doppler flow was measured in culprit and reference coronary arteries to calculate coronary flow velocity reserve (CFVR), baseline (BMR) and hyperaemic (HMR) microvascular resistance. Results The median admission glucose was 8.3 (7.2–9.6) mmol/l respectively 149.4 mg/dl [129.6–172.8] and was significantly associated with peak troponin T (standardised beta coefficient [std beta] = 0.281; p = 0.043). Multivariate analysis revealed that increasing glucose levels were significantly associated with a decrease in reference vessel CFVR (std beta = −0.313; p = 0.002), dictated by an increase in rest average peak velocity (APV) (std beta = 0.216; p = 0.033), due to a decreasing BMR (std beta = −0.225; p = 0.038) in the acute setting after PPCI. These associations disappeared at follow-up. These associations were not found for the infarct-related artery. Conclusion Elevated admission glucose levels are associated with impaired microvascular function assessed directly after PPCI in first anterior-wall STEMI. This influence of glucose levels is an acute phenomenon and contributes to microvascular dysfunction through alterations in resting flow and baseline microvascular resistance.

Contains fulltext : 190517.pdf (Publisher’s version ) (Open Access) BACKGROUND: Coronary artery spasm may be the underlying mechanism in up to 10% of cases of acute coronary syndrome (ACS) and sudden cardiac death. Asian individuals exhibit a 3-times greater incidence of spasm than Caucasians; this is likely due to different types of mechanisms. Consequently, solid data is limited about the long-term prognosis in Caucasian patients presenting with ACS and/or out-of-hospital cardiac arrest (OHCA) caused by coronary spasm. METHODS: Between 2002 and 2015, thirty Caucasian patients with coronary artery spasm presenting with ACS (N = 29) and/or OHCA (N = 11) were enrolled in this prospective registry. Follow-up, consisting of regular outpatient visits, was conducted with a mean follow-up period of 7.5 +/- 3.3 years. Outcomes included presence of stable angina pectoris, recurrence of ACS, occurrence of implantable cardioverter defibrillator (ICD) shocks and death. RESULTS: The majority of patients (60%) remained asymptomatic during the entire follow-up period. At the end of the follow-up period only 3 patients still experienced stable angina (10%). Only 2 patients (7%) had a recurrent cardiac event, in which the ICD provided appropriate shock therapy. Half of the patients treated with stenting (N = 6), required re-interventions. CONCLUSION: Coronary spasm with ACS and/or OHCA in a Caucasian patient cohort has a relatively benign prognosis in the majority of patients in long-term follow-up, if treated appropriately with medical therapy. Both the role of ICD in OHCA secondary to coronary spasm, and the efficacy of stenting to treat vasospastic angina, warrant further study in large-sized prospective clinical trials.

Background— The Navvus pressure sensor–equipped microcatheter allows to measure functional stenosis severity over a work-horse guidewire and is used as a more feasible alternative to regular sensor-equipped wires. However, Navvus is larger in diameter than contemporary sensor-equipped guidewires and may, thereby, influence functional measurements. The present study evaluates the hemodynamic influence of the Navvus microcatheter. Methods and Results— In patients with intermediate coronary stenosis, coronary pressure and flow velocity were measured using a dual sensor–equipped guidewire before and after introduction of Navvus. Patients were randomized to microcatheter-first or guidewire-first measurement. The primary end point was the difference in hyperemic stenosis resistance index between measurements before and after introduction of Navvus. Measurements were completed in 28 patients (28 stenoses). Mean hyperemic stenosis resistance was 0.37±0.19 Hg/cm/s for wire-only assessment and 0.48±0.26 Hg/cm/s after Navvus introduction ( P P =0.001). Passing–Bablok analysis revealed absence of a constant difference but significant proportional difference between the methods. Mean fractional flow reserve was 0.86±0.06 for wire-only assessment and 0.82±0.07 after Navvus introduction ( P P =0.036). Passing–Bablok analysis revealed significant constant and proportional differences between methods. Similar results were documented for resting indices of stenosis severity. Conclusions— Introduction of the Navvus microcatheter leads to clinically relevant stenosis severity overestimation in intermediate stenosis.