High-Risk Myocardial Infarction Database Research Articles

Non-fatal cardiovascular events preceding sudden cardiac death in patients with an acute myocardial infarction complicated by heart failure: insights from the high-risk myocardial infarction database.

Among patients with acute myocardial infarction (AMI) complicated by heart failure [HF; clinical HF or left ventricular (LV) systolic dysfunction], we explored the probability of subsequent non-fatal cardiovascular (CV) events and sudden cardiac death (SCD). The high-risk myocardial infarction (HRMI) database contains 28771 patients with signs of HF or reduced LV ejection fraction (<40%) after AMI. We evaluated the temporal association between SCD with preceding non-fatal CV event [HF hospitalization, recurrent myocardial infarction (MI), or stroke]. Median follow-up was 1.9 years. Mean age was 65.0 ± 11.5 years and 70% were male. The incidence of CV death was 7.9 per 100 patient-years and for SCD was 3.1 per patient-years (40% of CV deaths). The incidence of SCD preceded by HF hospitalization was greater than SCD without preceding HF hospitalization (P < 0.05). However, overall, SCD was less likely to be preceded by a non-fatal CV event compared to other causes of death: 9.6% of SCD events were preceded by an MI (vs. 46.6% for non-sudden CV death); 17.0% of SCD events were preceded with an HF hospitalization (vs. 25.4% for non-sudden CV death); and 2.7% of SCD events were preceded by stroke (vs.12.9% for non-sudden CV death). Among patients with AMI complicated by HF, SCD, compared with other causes of death, was less likely to be preceded by a non-fatal CV event. As patients are less likely to have preceding non-fatal CV events to alert the healthcare team of a possible impending SCD event, additional strategies for risk stratification for SCD are needed.

Association of diabetes and kidney function according to age and systolic function with the incidence of sudden cardiac death and non-sudden cardiac death in myocardial infarction survivors with heart failure.

An implantable cardioverter-defibrillator (ICD) is recommended for reducing the risk of sudden cardiac death (SCD) in myocardial infarction (MI) patients with a left ventricular ejection fraction (LVEF) ≤ 30%, as well as patients with a LVEF ≤ 35% and heart failure symptoms. Diabetes and/or impaired kidney function may confer additional SCD risk. We assessed the association between these two risk factors with SCD and non-SCD among MI survivors taking account of age and LVEF. A total of 17 773 patients from the High-Risk MI Database were evaluated. Overall, diabetes and estimated glomerular filtration rate < 60 mL/min/1.73 m2 , individually and together, conferred a higher risk of SCD [adjusted competing risk: hazard ratio (HR) 1.23, 1.23, and 1.32, respectively; all P < 0.03] and non-SCD (HR 1.34, 1.52, and 2.13, respectively; all P < 0.0001). Annual SCD rates in patients with LVEF > 35% and with diabetes, impaired kidney function, or both (2.0%, 2.5% and 2.7%, respectively) were comparable to rates observed in patients with LVEF 30-35% but no such risk factors (1.7%). However, these patients had also similarly higher non-SCD rates, such that the ratio of SCD to non-SCD was not increased. Importantly, this ratio was mostly dependent on age, with higher overall ratios in youngest subgroups (0.89 in patients < 55 years vs. 0.38 in patients ≥ 75 years), regardless of risk factors. Although MI survivors with LVEF > 35% with diabetes, impaired kidney function, or both are at increased risk of SCD, the risk of non-SCD risk is even higher, suggesting an extension of the current indication for an ICD to them is unlikely to be worthwhile. MI survivors with low LVEF and aged < 55 years are likely to have the greatest potential benefit from ICD implantation.

A history of diabetes predicts outcomes following myocardial infarction: an analysis of the 28 771 patients in the High-Risk MI Database.

To examine the impact of diabetes mellitus on long-term clinical outcomes in patients with myocardial infarction (MI) complicated by clinical signs of heart failure (HF) or left ventricular dysfunction (LVD). The High-Risk MI Database consists of individual data from 28 771 patients and was created by merging four large recent randomized clinical trials (VALIANT, EPHESUS, OPTIMAAL, and CAPRICORN) that each examined the impact of pharmacological interventions following MI in patients with evidence of HF or LVD. The mean age of patients was 65 years, 70% were male, and almost 94% Caucasian. Overall, 7368 (26%) had a history of diabetes. All the major outcomes were adjudicated by independent end-point committees. Strong and highly significant associations were found with all major clinical outcomes. Diabetes was associated with an increased risk for all-cause death [adjusted hazard ratio (HR) 1.37; confidence interval (CI) 1.28-1.46; P < 0.001]. The higher risk for all-cause death was largely mediated by higher risk for cardiovascular death (adjusted HR 1.38; CI 1.27-1.48; P < 0.001) predominantly due to a substantially increased risk for fatal re-infarction (adjusted HR 1.78; CI 1.42-2.23; P < 0.001). Additionally, diabetes was associated with an increased risk for hospitalizations, particularly HF hospitalization (adjusted HR 1.50; CI 1.39-1.63; P < 0.001). There were also elevated risks for composite outcomes, particularly death or hospitalization due to HF (adjusted HR 1.48; CI 1.38-1.59; P < 0.001). The risk for adverse outcomes associated with diabetes remains elevated even after debut of coronary artery disease in patients with MI complicated by clinical signs of HF or LVD. This association is particularly strong for HF-related outcomes.

Association of digitalis treatment with outcomes following myocardial infarction in patients with heart failure or evidence of left ventricular dysfunction: an analysis from the High-Risk Myocardial Infarction Database Initiative

Contradictory findings have been reported regarding the safety and efficacy of digitalis in patients recovering from acute myocardial infarction (MI). We studied the association of digitalis use with long-term and short-term prognosis in patients presenting with an acute MI complicated with heart failure (HF), left ventricular dysfunction, or both. Using the High-Risk MI Database Initiative combining data from 4 major clinical trials, totaling 27,673 patients, we investigated the association between digitalis use at baseline (3093 patients with digitalis and 24,580 without) with the rate of all-cause death, sudden cardiac death, cardiovascular death, HF hospitalization and the combination of the latter two, over a mean follow-up time of 2.7years. Patients with and without atrial fibrillation (AF) were studied separately. After a propensity score-based analysis, among patients without AF, those receiving digitalis experienced a higher rate of all-cause [hazard ratio (HR) 1.54, 95% confidence interval (CI) 1.42-1.67] and sudden cardiac death (HR 1.65, 95% CI 1.44-1.89), compared to those not receiving digitalis; similar results were found for the other 3 endpoints (all HR around 1.6). In contrast, in AF patients, digitalis had a milder effect on all outcomes (all HR≤1.12), with significant association only for the composite endpoint (HR 1.10, 95% CI 1.00-1.21, p=0.049); comparable results were obtained at 30days. Finally, the detrimental effect associated with digitalis use appeared to be more pronounced in patients with ejection fraction ≥ 40%. In MI survivors with HF and/or systolic dysfunction, digitalis was associated with a significant increased risk of death in patients without AF with mild to neutral associations for patients with AF. These findings raise concerns regarding the safety of digitalis in MI survivors with HF, especially for those without AF.

Association of beta-blocker treatment with mortality following myocardial infarction in patients with chronic obstructive pulmonary disease and heart failure or left ventricular dysfunction: a propensity matched-cohort analysis from the High-Risk Myocardial Infarction Database Initiative.

To determine the influence of baseline beta-blocker use on long-term prognosis of myocardial infarction (MI) survivors complicated with heart failure (HF) or with left ventricular dysfunction and with history of chronic obstructive pulmonary disease (COPD). Among the 28 771 patients from the High-Risk MI Database Initiative we identified 1573 patients with a baseline history of COPD. We evaluated the association between beta-blocker use at baseline (822 with beta-blocker and 751 without) on the rates of all-cause and cardiovascular mortality. On univariable Cox analysis, beta-blocker use was found to be associated with lower rates of both all-cause [hazard ratio (HR) = 0.61, 95% confidence interval (CI) 0.51-0.75, P < 0.0001] and cardiovascular mortality (HR = 0.63, 95% CI 0.51-0.78, P < 0.0001). After extensive adjustment for confounding, including 24 baseline covariates, COPD patients still benefited from beta-blocker usage (HR = 0.73, 95% CI 0.60-0.90, P = 0.002 for all-cause mortality; HR = 0.77, 95% CI 0.61-0.97, P = 0.025 for cardiovascular mortality). Adjusting for propensity scores (PS) constructed from the 24 aforementioned baseline characteristics provided similar results. In a cohort of 561 pairs of patients taking or not taking beta-blocker matched on PS using a 1:1 nearest-neighbour matching method, patients treated with beta-blocker experienced fewer all-cause deaths (HR = 0.71, 95% CI 0.56-0.89, P = 0.003) and cardiovascular deaths (HR = 0.76, 95% CI 0.59-0.97, P = 0.032). In the specific setting of a well-treated cohort of high-risk MI survivors, beta-blockers were associated with better outcomes in patients with COPD.