Effect of Cangrelor on Infarct Size in ST-Segment-Elevation Myocardial Infarction Treated by Primary Percutaneous Coronary Intervention: A Randomized Controlled Trial (The PITRI Trial).

BACKGROUND: The administration of intravenous cangrelor at reperfusion achieves faster onset of platelet P2Y12 inhibition than oral ticagrelor and has been shown to reduce myocardial infarction (MI) size in the preclinical setting. We hypothesized that the administration of cangrelor at reperfusion will reduce MI size and prevent microvascular obstruction in patients with ST-segment-elevation MI undergoing primary percutaneous coronary intervention. METHODS: This was a phase 2, multicenter, randomized, double-blind, placebo-controlled clinical trial conducted between November 2017 to November 2021 in 6 cardiac centers in Singapore. Patients were randomized to receive either cangrelor or placebo initiated before the primary percutaneous coronary intervention procedure on top of oral ticagrelor. The key exclusion criteria included presenting <6 hours of symptom onset; previous MI and stroke or transient ischemic attack; on concomitant oral anticoagulants; and a contraindication for cardiovascular magnetic resonance. The primary efficacy end point was acute MI size by cardiovascular magnetic resonance within the first week expressed as percentage of the left ventricle mass (%LVmass). Microvascular obstruction was identified as areas of dark core of hypoenhancement within areas of late gadolinium enhancement. The primary safety end point was Bleeding Academic Research Consortium-defined major bleeding in the first 48 hours. Continuous variables were compared by Mann-Whitney U test (reported as median [first quartile-third quartile]), and categorical variables were compared by Fisher exact test. A 2-sided P<0.05 was considered statistically significant. RESULTS: Of 209 recruited patients, 164 patients (78%) completed the acute cardiovascular magnetic resonance scan. There were no significant differences in acute MI size (placebo, 14.9% [7.3-22.6] %LVmass versus cangrelor, 16.3 [9.9-24.4] %LVmass; P=0.40) or the incidence (placebo, 48% versus cangrelor, 47%; P=0.99) and extent of microvascular obstruction (placebo, 1.63 [0.60-4.65] %LVmass versus cangrelor, 1.18 [0.53-3.37] %LVmass; P=0.46) between placebo and cangrelor despite a 2-fold decrease in platelet reactivity with cangrelor. There were no Bleeding Academic Research Consortium-defined major bleeding events in either group in the first 48 hours. CONCLUSIONS: Cangrelor administered at the time of primary percutaneous coronary intervention did not reduce acute MI size or prevent microvascular obstruction in patients with ST-segment-elevation MI given oral ticagrelor despite a significant reduction of platelet reactivity during the percutaneous coronary intervention procedure. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03102723.

Remote intensive management to improve antiplatelet adherence in acute myocardial infarction: a secondary analysis of the randomized controlled IMMACULATE trial.

This study aim to investigate if remote intensive coaching for the first 6 months post-AMI will improve adherence to the twice-a-day antiplatelet medication, ticagrelor. Between July 8, 2015, to March 29, 2019, AMI patients were randomly assigned to remote intensive management (RIM) or standard care (SC). RIM participants underwent 6 months of weekly then two-weekly consultations to review medication side effects and medication adherence coaching by a centralized nurse practitioner team, whereas SC participants received usual cardiologist face-to-face consultations. Adherence to ticagrelor were determined using pill counting and serial platelet reactivity measurements for 12 months. A total of 149 (49.5%) of participants were randomized to RIM and 152 (50.5%) to SC. Adherence to ticagrelor was similar between RIM and SC group at 1 month (94.4 ± 0.7% vs. 93.6±14.7%, p = 0.537), 6 months (91.0±14.6% vs. 90.6±14.8%, p = 0.832) and 12 months (87.4±17.0% vs. 89.8±12.5%, p = 0.688). There was also no significant difference in platelet reactivity between the RIM and SC groups at 1 month (251AU*min [212-328] vs. 267AU*min [208-351], p = 0.399), 6 months (239AU*min [165-308] vs. 235AU*min [171-346], p = 0.610) and 12 months (249AU*min [177-432] vs. 259AU*min [182-360], p = 0.678). Sensitivity analysis did not demonstrate any association of ticagrelor adherence with bleeding events and major adverse cardiovascular events. RIM, comprising 6 months of intensive coaching by nurse practitioners, did not improve adherence to the twice-a-day medication ticagrelor compared with SC among patients with AMI. A gradual decline in ticagrelor adherence over 12 months was observed despite 6 months of intensive coaching.

De-escalation or abbreviation of dual antiplatelet therapy in acute coronary syndromes and percutaneous coronary intervention: a Consensus Statement from an international expert panel on coronary thrombosis.

Conventional dual antiplatelet therapy (DAPT) for patients with acute coronary syndromes undergoing percutaneous coronary intervention comprises aspirin with a potent P2Y purinoceptor 12 (P2Y12) inhibitor (prasugrel or ticagrelor) for 12 months. Although this approach reduces ischaemic risk, patients are exposed to a substantial risk of bleeding. Strategies to reduce bleeding include de-escalation of DAPT intensity (downgrading from potent P2Y12 inhibitor at conventional doses to either clopidogrel or reduced-dose prasugrel) or abbreviation of DAPT duration. Either strategy requires assessment of the ischaemic and bleeding risks of each individual. De-escalation of DAPT intensity can reduce bleeding without increasing ischaemic events and can be guided by platelet function testing or genotyping. Abbreviation of DAPT duration after 1-6 months, followed by monotherapy with aspirin or a P2Y12 inhibitor, reduces bleeding without an increase in ischaemic events in patients at high bleeding risk, particularly those without high ischaemic risk. However, these two strategies have not yet been compared in a head-to-head clinical trial. In this Consensus Statement, we summarize the evidence base for these treatment approaches, provide guidance on the assessment of ischaemic and bleeding risks, and provide consensus statements from an international panel of experts to help clinicians to optimize these DAPT approaches for individual patients to improve outcomes.

High frequency of anti-DSG 2 antibodies in post COVID-19 serum samples.

BACKGROUND: There is growing recognition that COVID-19 does cause cardiac sequelae. The underlying mechanisms involved are still poorly understood to date. Viral infections, including COVID-19, have been hypothesized to contribute to autoimmunity, by exposing previously hidden cryptic epitopes on damaged cells to an activated immune system. Given the high incidence of cardiac involvement seen in COVID-19, our aim was to determine the frequency of anti-DSG2 antibodies in a population of post COVID-19 patients. METHODS AND RESULTS: 300 convalescent serum samples were obtained from a group of post COVID-19 infected patients from October 2020 to February 2021. 154 samples were drawn 6 months post-COVID-19 infection and 146 samples were drawn 9 months post COVID infection. 17 samples were obtained from the same patient at the 6- and 9- month mark. An electrochemiluminescent-based immunoassay utilizing the extracellular domain of DSG2 for antibody capture was used. The mean signal intensity of anti-DSG2 antibodies in the post COVID-19 samples was significantly higher than that of a healthy control population (19 ± 83.2 in the post-COVID-19 sample vs. 2.1 ± 7.2 (p < 0. 0001) in the negative control healthy population). Of note, 29.3% of the post COVID-19 infection samples demonstrated a signal higher than the 90th percentile of the control population and 8.7% were higher than the median found in ARVC patients. The signal intensity between the 6-month and 9-month samples did not differ significantly. CONCLUSIONS: We report for the first time that recovered COVID-19 patients demonstrate significantly higher and sustained levels of anti-DSG2 autoantibodies as compared to a healthy control population, comparable to that of a diagnosed ARVC group.

Robust Performance of Potentially Functional SNPs in Machine Learning Models for the Prediction of Atorvastatin-Induced Myalgia.

Statins can cause muscle symptoms resulting in poor adherence to therapy and increased cardiovascular risk. We hypothesize that combinations of potentially functional SNPs (pfSNPs), rather than individual SNPs, better predict myalgia in patients on atorvastatin. This study assesses the value of potentially functional single nucleotide polymorphisms (pfSNPs) and employs six machine learning algorithms to identify the combination of SNPs that best predict myalgia. Methods: Whole genome sequencing of 183 Chinese, Malay and Indian patients from Singapore was conducted to identify genetic variants associated with atorvastatin induced myalgia. To adjust for confounding factors, demographic and clinical characteristics were also examined for their association with myalgia. The top factor, sex, was then used as a covariate in the whole genome association analyses. Variants that were highly associated with myalgia from this and previous studies were extracted, assessed for potential functionality (pfSNPs) and incorporated into six machine learning models. Predictive performance of a combination of different models and inputs were compared using the average cross validation area under ROC curve (AUC). The minimum combination of SNPs to achieve maximum sensitivity and specificity as determined by AUC, that predict atorvastatin-induced myalgia in most, if not all the six machine learning models was determined. Results: Through whole genome association analyses using sex as a covariate, a larger proportion of pfSNPs compared to non-pf SNPs were found to be highly associated with myalgia. Although none of the individual SNPs achieved genome wide significance in univariate analyses, machine learning models identified a combination of 15 SNPs that predict myalgia with good predictive performance (AUC >0.9). SNPs within genes identified in this study significantly outperformed SNPs within genes previously reported to be associated with myalgia. pfSNPs were found to be more robust in predicting myalgia, outperforming non-pf SNPs in the majority of machine learning models tested. Conclusion: Combinations of pfSNPs that were consistently identified by different machine learning models to have high predictive performance have good potential to be clinically useful for predicting atorvastatin-induced myalgia once validated against an independent cohort of patients.

Multiparametric exercise stress cardiovascular magnetic resonance in the diagnosis of coronary artery disease: the EMPIRE trial.

BACKGROUND: Stress cardiovascular magnetic resonance (CMR) offers assessment of ventricular function, myocardial perfusion and viability in a single examination to detect coronary artery disease (CAD). We developed an in-scanner exercise stress CMR (ExCMR) protocol using supine cycle ergometer and aimed to examine the diagnostic value of a multiparametric approach in patients with suspected CAD, compared with invasive fractional flow reserve (FFR) as the reference gold standard. METHODS: In this single-centre prospective study, patients who had symptoms of angina and at least one cardiovascular disease risk factor underwent both ExCMR and invasive angiography with FFR. Rest-based left ventricular function (ejection fraction, regional wall motion abnormalities), tissue characteristics and exercise stress-derived (perfusion defects, inducible regional wall motion abnormalities and peak exercise cardiac index percentile-rank) CMR parameters were evaluated in the study. RESULTS: In the 60 recruited patients with intermediate CAD risk, 50% had haemodynamically significant CAD based on FFR. Of all the CMR parameters assessed, the late gadolinium enhancement, stress-inducible regional wall motion abnormalities, perfusion defects and peak exercise cardiac index percentile-rank were independently associated with FFR-positive CAD. Indeed, this multiparametric approach offered the highest incremental diagnostic value compared to a clinical risk model (χ2 for the diagnosis of FFR-positive increased from 7.6 to 55.9; P < 0.001) and excellent performance [c-statistic area under the curve 0.97 (95% CI: 0.94-1.00)] in discriminating between FFR-normal and FFR-positive patients. CONCLUSION: The study demonstrates the clinical potential of using in-scanner multiparametric ExCMR to accurately diagnose CAD. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03217227, Registered 11 July 2017-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03217227?id=NCT03217227&draw=2&rank=1&load=cart.

Remote Postdischarge Treatment of Patients With Acute Myocardial Infarction by Allied Health Care Practitioners vs Standard Care: The IMMACULATE Randomized Clinical Trial.

Importance: There are few data on remote postdischarge treatment of patients with acute myocardial infarction. Objective: To compare the safety and efficacy of allied health care practitioner-led remote intensive management (RIM) with cardiologist-led standard care (SC). Design, Setting, and Participants: This intention-to-treat feasibility trial randomized patients with acute myocardial infarction undergoing early revascularization and with N-terminal-pro-B-type natriuretic peptide concentration more than 300 pg/mL to RIM or SC across 3 hospitals in Singapore from July 8, 2015, to March 29, 2019. RIM participants underwent 6 months of remote consultations that included ß-blocker and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACE-I/ARB) dose adjustment by a centralized nurse practitioner team while SC participants were treated face-to-face by their cardiologists. Main Outcomes and Measures: The primary safety end point was a composite of hypotension, bradycardia, hyperkalemia, or acute kidney injury requiring hospitalization. To assess the efficacy of RIM in dose adjustment of ß-blockers and ACE-I/ARBs compared with SC, dose intensity scores were derived by converting comparable doses of different ß-blockers and ACE-I/ARBs to a scale from 0 to 5. The primary efficacy end point was the 6-month indexed left ventricular end-systolic volume (LVESV) adjusted for baseline LVESV. Results: Of 301 participants, 149 (49.5%) were randomized to RIM and 152 (50.5%) to SC. RIM and SC participants had similar mean (SD) age (55.3 [8.5] vs 54.7 [9.1] years), median (interquartile range) N-terminal-pro-B-type natriuretic peptide concentration (807 [524-1360] vs 819 [485-1320] pg/mL), mean (SD) baseline left ventricular ejection fraction (57.4% [11.1%] vs 58.1% [10.3%]), and mean (SD) indexed LVESV (32.4 [14.1] vs 30.6 [11.7] mL/m2); 15 patients [5.9%] had a left ventricular ejection fraction <40%. The primary safety end point occurred in 0 RIM vs 2 SC participants (1.4%) (P = .50). The mean ß-blocker and ACE-I/ARB dose intensity score at 6 months was 3.03 vs 2.91 (adjusted mean difference, 0.12 [95% CI, -0.02 to 0.26; P = .10]) and 2.96 vs 2.77 (adjusted mean difference, 0.19 [95% CI, -0.02 to 0.40; P = .07]), respectively. The 6-month indexed LVESV was 28.9 vs 29.7 mL/m2 (adjusted mean difference, -0.80 mL/m2 [95% CI, -3.20 to 1.60; P = .51]). Conclusions and Relevance: Among low-risk patients with revascularization after myocardial infarction, RIM by allied health care professionals was feasible and safe. There were no differences in achieved medication doses or indices of left ventricular remodeling. Further studies of RIM in higher-risk cohorts are warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT02468349.

Beta-blockers and renin-angiotensin system inhibitors in acute myocardial infarction managed with inhospital coronary revascularization.

Pivotal trials of beta-blockers (BB) and angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB) in acute myocardial infarction (AMI) were largely conducted prior to the widespread adoption of early revascularization. A total of 15,073 patients with AMI who underwent inhospital coronary revascularization from January 2007 to December 2013 were analyzed. At 12 months, BB was significantly associated with a lower incidence of major adverse cardiovascular events (MACE, adjusted HR 0.80, 95% CI 0.70-0.93) and all-cause mortality (adjusted HR 0.69, 95% CI 0.55-0.88), while ACEI/ARB was significantly associated with lower all-cause mortality (adjusted HR 0.80, 95% CI 0.66-0.98) and heart failure (HF) hospitalization (adjusted HR 0.80, 95% CI 0.68-0.95). Combined BB and ACEI/ARB use was associated with the lowest incidence of MACE (adjusted HR 0.70, 95% CI 0.57-0.86), all-cause mortality (adjusted HR 0.55, 95% CI 0.40-0.77) and HF hospitalization (adjusted HR 0.64, 95% CI 0.48-0.86). This were consistent for left ventricular ejection fraction < 50% or ≥ 50%. In conclusion, in AMI managed with revascularization, both BB and ACEI/ARB were associated with a lower incidence of 12-month all-cause mortality. Combined BB and ACEI/ARB was associated with the lowest incidence of all-cause mortality and HF hospitalization.

Independent Predictors of Cardiac Mortality and Hospitalization for Heart Failure in a Multi-Ethnic Asian ST-segment Elevation Myocardial Infarction Population Treated by Primary Percutaneous Coronary Intervention.

We aimed to identify independent predictors of cardiac mortality and hospitalization for heart failure (HHF) from a real-world, multi-ethnic Asian registry [the Singapore Myocardial Infarction Registry] of ST-segment elevation myocardial infarction (STEMI) patients treated by primary percutaneous coronary intervention. 11,546 eligible STEMI patients between 2008 and 2015 were identified. In-hospital, 30-day and 1-year cardiac mortality and 1-year HHF rates were 6.4%, 6.8%, 8.3% and 5.2%, respectively. From the derivation cohort (70% of patients), age, Killip class and cardiac arrest, creatinine, hemoglobin and troponin on admission and left ventricular ejection fraction (LVEF) during hospitalization were predictors of in-hospital, 30-day and 1-year cardiac mortality. Previous ischemic heart disease (IHD) was a predictor of in-hospital and 30-day cardiac mortality only, whereas diabetes was a predictor of 1-year cardiac mortality only. Age, previous IHD and diabetes, Killip class, creatinine, hemoglobin and troponin on admission, symptom-to-balloon-time and LVEF were predictors of 1-year HHF. The c-statistics were 0.921, 0.901, 0.881, 0.869, respectively. Applying these models to the validation cohort (30% of patients) showed good fit and discrimination (c-statistic 0.922, 0.913, 0.903 and 0.855 respectively; misclassification rate 14.0%, 14.7%, 16.2% and 24.0% respectively). These predictors could be incorporated into specific risk scores to stratify reperfused STEMI patients by their risk level for targeted intervention.

Sex Differences in 1-Year Rehospitalization for Heart Failure and Myocardial Infarction After Primary Percutaneous Coronary Intervention.

It is unclear whether universal access to primary percutaneous coronary intervention (pPCI) may reduce sex differences in 1-year rehospitalization for heart failure (HF) and myocardial infarction (MI) after ST-elevation myocardial infarction (STEMI). We studied 7,597 consecutive STEMI patients (13.8% women, n = 1,045) who underwent pPCI from January 2007 to December 2013. Cox regression models adjusted for competing risk from death were used to assess sex differences in rehospitalization for HF and MI within 1 year from discharge. Compared with men, women were older (median age 67.6 vs 56.0 years, p < 0.001) with higher prevalence of co-morbidities and multivessel disease. Women had longer median door-to-balloon time (76 vs 66 minutes, p < 0.001) and were less likely to receive drug-eluting stents (19.5% vs 24.1%, p = 0.001). Of the medications prescribed at discharge, fewer women received aspirin (95.8% vs 97.6%, p = 0.002) and P2Y12 antagonists (97.6% vs 98.5%, p = 0.039), but there were no significant sex differences in other discharge medications. After adjusting for differences in baseline characteristics and treatment, sex differences in risk of rehospitalization for HF attenuated (hazard ratio [HR] 1.05, 95% confidence interval [CI] 0.79 to 1.40), but persisted for MI (HR 1.68, 95% CI 1.22 to 2.33), with greater disparity in patients aged ≥60 years (HR 1.83, 95% CI 1.18 to 2.85) than those aged <60 years (HR 1.45, 95% CI 0.84 to 2.50). In conclusion, in a setting of universal access to pPCI, the adjusted risk of 1-year rehospitalization for HF was similar in both sexes, but women had significantly higher adjusted risk of 1-year rehospitalization for MI, especially older women.

Platelet inhibition to target reperfusion injury trial: Rationale and study design.

BACKGROUND: In ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (PPCI), current oral P2Y12 platelet inhibitors do not provide maximal platelet inhibition at the time of reperfusion. Furthermore, administration of cangrelor prior to reperfusion has been shown in pre-clinical studies to reduce myocardial infarct (MI) size. Therefore, we hypothesize that cangrelor administered prior to reperfusion in STEMI patients will reduce the incidence of microvascular obstruction (MVO) and limit MI size in STEMI patients treated with PPCI. METHODS: The platelet inhibition to target reperfusion injury (PITRI) trial, is a phase 2A, multi-center, double-blinded, randomized controlled trial, in which 210 STEMI patients will be randomized to receive either an intravenous (IV) bolus of cangrelor (30 µg/kg) followed by a 120-minute infusion (4 µg/kg/min) or matching saline placebo, initiated prior to reperfusion (NCT03102723). RESULTS: The study started in October 2017 and the anticipated end date would be July 2020. The primary end-point will be MI size quantified by cardiovascular magnetic resonance (CMR) on day 3 post-PPCI. Secondary endpoints will include markers of reperfusion, incidence of MVO, MI size, and adverse left ventricular remodeling at 6 months, and major adverse cardiac and cerebrovascular events. SUMMARY: The aim of the PITRI trial is to assess whether cangrelor administered prior to reperfusion would reduce acute MI size and MVO, as assessed by CMR.

Incidence and predictors of left ventricular thrombus by cardiovascular magnetic resonance in acute ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention: a meta-analysis.

INTRODUCTION: The incidence of left ventricular (LV) thrombus formation in ST-segment elevation myocardial infarction (STEMI) patients in the current era of primary percutaneous coronary intervention (PCI) is not well established. We performed a meta-analysis to assess the actual incidence and predictors of LV thrombus by cardiovascular magnetic resonance (CMR) in STEMI treated by primary PCI. METHODS: We searched MEDLINE and EMBASE databases up to February 2018. We included all studies published as a full-text article, reporting the incidence of LV thrombus by CMR within 1 month following acute STEMI in patients treated by primary PCI. A binary random-effects model was used to estimate the pooled incidence of LV thrombus. The diagnostic performance of transthoracic echocardiography (TTE) as compared with CMR was pooled to obtain the sensitivity and specificity of TTE with CMR as the gold standard. Embolic and bleeding complications of LV thrombus were also evaluated. RESULTS: Ten studies were included in the meta-analysis. The incidence of LV thrombus by CMR in all-comer STEMI patients (n = 2072) was 6.3% with 96% of LV thrombus occurring in those with anterior STEMI (12.2% incidence). When only anterior STEMI with LVEF< 50% were considered (n = 447), the incidence of LV thrombus was 19.2%. Compared with CMR, the sensitivity of TTE to detect LV thrombus was 29% with a specificity of 98%. The sensitivity of TTE increased to 70% in those with anterior STEMI and reduced LVEF. LV thrombus resolved in 88% of cases by 3 to 6 months. After 1-2 years follow-up, the embolic complication rate was similar at 1.5% (P = 0.25) but the bleeding complication rate was significantly higher (8.8% versus 0.5%, P < 0.001) in the LV thrombus group on triple therapy when compared to the no LV thrombus group on dual antiplatelet therapy. CONCLUSION: In the primary PCI era, CMR detection of an LV thrombus post-STEMI remains high with incidence of nearly 20% in anterior STEMI with depressed LVEF. Patients with LV thrombus treated by triple therapy had similar embolic complications but higher bleeding complications than those with no LV thrombus treated with dual antiplatelet therapy. A 3 month follow-up CMR scan to guide anticoagulation duration might help mitigate bleeding risk.

Invasive Assessment of the Coronary Microcirculation in Reperfused ST-Segment-Elevation Myocardial Infarction Patients: Where Do We Stand?

For patients presenting with an acute ST-segment-elevation myocardial infarction, the most effective therapy for reducing myocardial infarct size and preserving left ventricular systolic function is primary percutaneous coronary intervention (PPCI). However, mortality and morbidity remain significant. This is partly attributed to the development of microvascular obstruction, which occurs in around 50% of ST-segment-elevation myocardial infarction patients post-PPCI, and it is associated with adverse left ventricular remodeling and worse clinical outcomes. Although microvascular obstruction can be detected by cardiac imaging techniques several hours post-PPCI, it may be too late to intervene at that time. Therefore, being able to predict the development of microvascular obstruction at the time of PPCI may identify high-risk patients who might benefit from further adjuvant intracoronary therapies, such as thrombolysis, vasodilators, glycoprotein IIb/IIIa inhibitors, and anti-inflammatory agents that may reduce microvascular obstruction. Recent studies have shown that invasive coronary physiology measurements performed during PPCI can be used to assess the coronary microcirculation. In this article, we provide an overview of the various invasive methods currently available to assess the coronary microcirculation in the setting of ST-segment-elevation myocardial infarction, and how they could potentially be used in the future for tailoring therapies to those most at risk.

Impact of timing to coronary angiography in acute coronary syndrome on contemporary clinical practice.

Recent studies appear to suggest a correlation between timing to coronary angiography and clinical outcome among patients with acute coronary syndrome (ACS). We aim to study 12-month outcomes of ACS patients who are stratified according to early (≤24 hours), intermediate (>24 to <48 hours) and delayed (≥48 hours) coronary angiography. This is a prospective observational study of patients with ACS defined as either unstable angina pectoris or non-ST elevation myocardial infarction (MI) admitted between October 2008 and July 2009. Baseline clinical characteristics of age, gender, cardiovascular risk factors (diabetes mellitus, hypertension, dyslipidemia) and TIMI score were analyzed and adjusted for outcomes. The primary outcome was combined major adverse cardiovascular events (MACE) of death or non-fatal MI, as well as target vessel revascularization (TVR) up to 12 months. This study consisted of 642 patients (75% males, mean age 60±13) with median follow-up of 7 months and median TIMI score of 4. Over half (50.2%) were categorized as high-risk (TIMI score ≥4). 281 patients (43.5%) had early angiography, 170 (26.5%) had angiography between >24 to <48 hours and 191(30%) patients had delayed angiography ≥48 hours. In high-risk patients, the primary outcome occurred in 10.9% of patients in the early group, as compared with 13.2% in intermediate group and 23.9% in delayed group (p=0.015) at six months. However, in low-risk patients (TIMI scores <4), there was no significant difference between the groups (7.1% vs. 3.4% vs. 5.9%, p=0.316) at six months. Compared to the intermediate and delayed groups, patients in the early group had lower overall MACE at 12 months (21% vs. 14% vs. 10%, p=0.006) that was largely related to a lower frequency of death at 12 months (11% vs. 7% vs. 4.6%, p=0.03). There were no differences in rates of TVR between the groups (4% vs. 7% vs. 3.5%, p=0.14). In this observational analysis, an early strategy to coronary angiography was associated with improved survival at one year while an early to intermediate strategy benefitted the subgroup of high-risk patients with significant reductions in cardiovascular events at six months.

Comparing the use of cobalt chromium stents to stainless steel stents in primary percutaneous coronary intervention for acute myocardial infarction: a prospective registry.

OBJECTIVES: To determine clinical outcome and rates of target vessel revascularization (TVR) in patients undergoing primary percutaneous coronary intervention (PCI) for STEMI who were treated with cobalt-chromium stents compared to stainless steel bare metal stents (BMS). BACKGROUND: The newer generation cobalt chromium stents were reported to achieve lower rates of TVR compared with conventional BMS. METHODS: Consecutive STEMI cases admitted within 12 h of symptom onset and undergoing primary angioplasty and bare metal stent implantation 1 January 2002 and 31 December 2008 were identified. Primary outcomes were rates of clinically-driven TVR at six months as well as occurrence of major adverse cardiovascular events (MACE) either of all-cause death, repeat myocardial infarction or TVR at six months. RESULTS: 1030 cases with 1175 lesions (84% males) and median age of 58 years underwent primary PCI for STEMI in our registry. Overall procedural success rate was 98%. Stainless steel stents were inserted in 65% of the culprit lesions (stainless steel, n = 766 versus cobalt chromium, n = 264). Primary outcomes of TVR (3.5% in the stainless steel group and 3.4% in the cobalt chromium group, P = 0.93) and MACE (8.4% in the stainless steel group and 5.3% in the cobalt chromium group, P = 0.11) after six months were no different between the two groups. However, there were more deaths at 30 days in the stainless steel group compared to the cobalt chromium group (3.5% versus 0.4%, HR 4.04 (1.03-3.88), P = 0.04). CONCLUSION: Both cobalt-chromium and stainless steel coronary stents were associated with similar and low risk of clinically-driven TVR.