Circadian dependence of manual thrombus aspiration benefit in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

The impact of time-of-day reperfusion on remote ischemic conditioning in ST-elevation myocardial infarction: a RIC-STEMI substudy

Daytime variation affects the tolerance of cardiomyocytes to ischemia-reperfusion injury (IRI). This study aims to evaluate the impact of time-of-day reperfusion on clinical outcomes of remote ischemic conditioning (RIC) as an adjuvant to primary percutaneous coronary intervention(PPCI) in ST-elevation myocardial infarction(STEMI) patients. A post-hoc analysis of a prospective, single-center parallel 1:1 randomized trial (RIC-STEMI) was performed. This analysis included 448 STEMI patients previously randomized to either PPCI alone (PPCI group) (n = 217) or RIC as an adjuvant to PPCI (RIC + PPCI group) (n = 231). Moreover, the sample was divided according to the time of PPCI: night-morning (22 h-11h59min) (n = 216) or afternoon (12 h-21h59min) (n = 232) groups. The primary follow-up endpoint was a composite of cardiac death and hospitalization due to heart failure. There were no significant differences in the clinical characteristics and the follow-up outcomes between groups. The afternoon period (HR = 0.474; 95% CI 0.230-0.977; p = 0.043) and RIC (HR = 0.423; 95% CI 0.195-0.917; p = 0.029) were independent predictors of the primary follow-up endpoint. An univariate analysis showed a lower frequency of primary follow-up endpoint, just in the afternoon period (10.3%vs0.9%; p = 0.002), in the RIC + PPCI group. A multivariate analysis revealed that RIC was an independent predictor of the primary follow-up endpoint in the afternoon group (HR = 0.098; 95% CI 0.012-0.785; p = 0.029), but not in the night-morning group. In addition, the afternoon period was not an independent predictor of the primary follow-up endpoint when the multivariate analysis was performed in the PPCI group. In conclusion, this study showed an important cardioprotective effect of RIC, namely in the afternoon period, suggesting that the afternoon period enhances the cardioprotection induced by RIC.

Circadian rhythms in ischaemic heart disease: key aspects for preclinical and translational research: position paper of the ESC working group on cellular biology of the heart

Circadian rhythms are internal regulatory processes controlled by molecular clocks present in essentially every mammalian organ that temporally regulate major physiological functions. In the cardiovascular system, the circadian clock governs heart rate, blood pressure, cardiac metabolism, contractility, and coagulation. Recent experimental and clinical studies highlight the possible importance of circadian rhythms in the pathophysiology, outcome, or treatment success of cardiovascular disease, including ischaemic heart disease. Disturbances in circadian rhythms are associated with increased cardiovascular risk and worsen outcome. Therefore, it is important to consider circadian rhythms as a key research parameter to better understand cardiac physiology/pathology, and to improve the chances of translation and efficacy of cardiac therapies, including those for ischaemic heart disease. The aim of this Position Paper by the European Society of Cardiology Working Group Cellular Biology of the Heart is to highlight key aspects of circadian rhythms to consider for improvement of preclinical and translational studies related to ischaemic heart disease and cardioprotection. Applying these considerations to future studies may increase the potential for better translation of new treatments into successful clinical outcomes.

Relationship between primary percutaneous coronary intervention time of day, infarct size, microvascular obstruction and prognosis in ST-segment elevation myocardial infarction

BACKGROUND

Whether the time of day of primary percutaneous coronary intervention (pPCI) in patients with ST-segment elevation myocardial infarction (STEMI) is associated with infarct size, microvascular obstruction (MVO), and prognosis is uncertain. We compared infarct size assessed by cardiac MRI (CMR) and clinical outcomes in STEMI patients according to the pPCI time of day from a large, individual patient-data pooled database.

METHODS

We pooled patient-level data from five randomized pPCI trials in which infarct size was measured within 1 month by CMR. Patients were categorized according to the pPCI time of day.

RESULTS

Among 1519 patients with STEMI, 794 (52.2%) underwent pPCI between 8:00 h and 15:59 h, 431 (28.4%) between 16:00 h and 23:59 h, and 294 (19.4%) between 24:00 h and 7:59 h. Infarct size was assessed in 1331 patients at a median of 3.0 days (interquartile range 2.0-5.0) after pPCI. Compared with patients who underwent PCI between 8:00 h and 15:59 h, infarct size was not significantly different for patients undergoing PCI from 16:00 h to 23:59 h [adjusted difference -0.7%, 95% confidence interval (CI) -3.1 to 1.7%, P = 0.46] or 24:00 h to 7:59 h (adjusted difference 0.9%, 95% CI -1.2 to 3.1%, P = 0.29). The time of day of pPCI was also unrelated to MVO and the 1-year risks of death or heart failure hospitalization.

CONCLUSION

In this large-scale, individual patient data pooled analysis, no association was found between the time of day of pPCI and infarct size, MVO, or prognosis after STEMI.

Aspiration thrombectomy in ST-Elevation myocardial infarction: Further insights from a network meta-analysis of randomized trials

Background

The initial enthusiasm for thrombectomy during percutaneous coronary intervention (PCI) of ST-elevation myocardial infarction (STEMI) patients has given way to restraint. There has been some limited interest whether it is beneficial in a few selected subgroups. Hence, we performed a network meta-analysis to compare conventional PCI (cPCI), Aspiration or manual thrombectomy (AT) and Mechanical thrombectomy (McT) for clarification.

Methods

Electronic databases were searched for randomized studies that compared AT, McT, or cPCI. A network meta-analysis was performed and odd’s ratio (OR) with 95% confidence intervals was generated for major adverse cardiac events (MACE), mortality, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis (ST), stroke, left ventricular ejection fraction (LVEF), myocardial blush grade (MBG) and ST segment resolution (STR).

Results

A total of 43 randomized trials (n = 26,682) were included. The risk of MACE (OR 0.86 95% CI 0.73–1.00), Mortality (OR 0.85 95% CI 0.73–0.99), MI (OR 0.65, 95% CI: 0.44–0.95) and TVR (OR 0.86, 95% CI: 0.74–1.00) were lower with AT compared to cPCI. The risk of ST and stroke was no different with the use of adjunctive AT. MBG, STR, and LVEF improved with the use of AT while the infarct size was no different in the two groups.

Conclusions

Our comprehensive network meta-analysis suggests conflicting outcomes with AT. While Mortality, MACE, MI seem better, there is a suggestion that, Stroke and ST might be worse. Whether AT can still be pursued in any select cases should be further scrutinized.

Predictors of transportation delay in patients with suspected ST-elevation-myocardial infarction in the VIENNA-STEMI network

OBJECTIVE

The emergency medical service (EMS) provides rapid pre-hospital diagnosis and transportation in ST-elevation myocardial infarction (STEMI) systems of care. Aim of the study was to assess temporal and regional characteristics of EMS-related delays in a metropolitan STEMI network.

METHODS

Patient call-to-arrival of EMS at site (call-to-site), transportation time from site to hospital (site-to-door), call-to-door, patient's location, month, weekday, and hour of EMS activation were recorded in 4751 patients referred to a tertiary center with suspicion of STEMI.

RESULTS

Median call-to-site, site-to-door, and call-to-door times were 9 (7-12), 39 (31-48), and 49 (41-59) minutes, respectively. The shortest transportation times were noted between 08:00 and 16:00 and in general on Sundays. They were significantly prolonged between midnight and 04:00, whereby the longest difference did not exceed 4 min in median. Patient's site of call had a major impact on transportation times, which were shorter in Central and Western districts as compared to Southern and Eastern districts of Vienna (p < 0.001 between-group difference for call-to-site, site-to-door, and call-to-door). After multivariable adjustment, patient's site of call was an independent predictor of call-to-site delay (p < 0.001). Moreover, age and hour of EMS activation were the strongest predictors of call-to-site, site-to-door, and call-to-door delays (p < 0.05).

CONCLUSION

In our Viennese STEMI network, the strongest determinants of pre-hospital EMS-related transportation delays were patient's site of call, patient's age, and hour of EMS activation. Due to the significant but small median time delays, which are within the guideline-recommended time intervals, no impact on clinical outcome can be expected.

Polyhedral erythrocytes in intracoronary thrombus and their association with reperfusion in myocardial infarction

OBJECTIVE

The tightly packed arrays of polyhedral erythrocytes, polyhedrocytes, formed during thrombus contraction, have been detected in some intracoronary thrombi (ICT) obtained from patients with ST-segment elevation myocardial infarction (STEMI). We sought to investigate determinants of polyhedrocyte content in ICT and its association with reperfusion in STEMI.

METHODS

We assessed the composition of ICT obtained during thrombectomy within 12 h since the symptom onset in 110 STEMI patients, following 300 mg of aspirin (n = 110) and 600 mg of clopidogrel (n = 75). The predominance of fibrin, erythrocytes, polyhedrocytes or platelets was evaluated using scanning electron microscopy.

RESULTS

Polyhedrocytes were found in 34 (30.9%) ICT, in which they covered 20-50% (median 38.8%) fields of view. Patients with polyhedrocytes in ICT had lower median minimal reference infarct-related artery (IRA) diameter by 20% (p < 0.0001) and area by 31% (p < 0.0001) versus those without polyhedrocytes. Time of ischemia showed association with the polyhedrocyte content (r = 0.26, p = 0.007). By multivariate analysis, minimal IRA diameter (β = - 0.50, p < 0.0001) and ischemia time (β = 0.20, p = 0.035) independently affected polyhedrocyte content in ICT (R² = 0.45, p < 0.0001). Patients with ischemia time of > 3 h and polyhedrocytes present in ICT had more frequently TIMI-2/3 flow after thrombus aspiration (96% vs. 67%, p = 0.02) and final TIMI-2/3 myocardial perfusion grade (92% vs. 57%, p = 0.044) versus those without polyhedrocytes.

CONCLUSIONS

Our findings indicate that the presence of polyhedrocytes in ICT, observed in one-third of STEMI patients, is associated with smaller minimal IRA diameter, prolonged ischemia and their formation in late presenters is associated with more effective thrombus aspiration and better myocardial reperfusion.