Impact of the joint association between sex, age and diabetes on long-term mortality after acute myocardial infarction

BACKGROUND

The role of sex, and its joint effect with age and diabetes mellitus, on mortality subsequent to surviving an acute myocardial infarction (AMI) beyond 30 days are unclear. The high prevalence of diabetes mellitus in an ethnically diverse Asian population motivates this study.

METHODS

The study population comprised of a nationwide cohort of Asian patients with AMI, hospitalized between 2000 to 2005, who survived the first 30 days post-admission and were followed prospectively until death or 12 years.

RESULTS

Among the 13,389 survivors, there were fewer women (25.5%) who were older than men (median 70 vs. 58 years) and a larger proportion had diabetes mellitus at admission (51.4% vs. 31.4%). During follow-up 4,707 deaths (women 13.2%; men 22.0%) occurred, with women experiencing higher mortality than men with an averaged hazard ratio (HR): 2.08; 95% confidence interval : 1.96-2.20. However the actual adverse outcome, although always greater, reduced over time with an estimated HR: 2.23 (2.04-2.45) at 30 days to HR: 1.75; (1.47-2.09) 12 years later. The difference in mortality also declined with increasing age: HR 1.80 (1.52-2.13) for those aged 22-59, 1.26 (1.11-1.42) for 60-69, 1.06 (0.96-1.17) and 0.96 (0.85-1.09) for those 70-79 and 80-101 years. Significant two-factor interactions were observed between sex, age and diabetes (P < 0.001). Diabetic women <60 years of age had greater mortality than diabetic men of the same age (adjusted HR: 1.44; 1.14-1.84; P = 0.003), while diabetic women and men ≥60 years of age had a less pronounced mortality difference (adjusted HR: 1.12; 0.99-1.26).

CONCLUSIONS

One in two women hospitalized for AMI in this Asian cohort had diabetes and the sex disparity in post-MI mortality was most pronounced among these who were <60 years of age. This underscores the need for better secondary prevention in this high-risk group.

Declining mortality rates despite increases in clinical coronary artery disease among US dialysis patients: a national registry study

BACKGROUND/AIMS

Coronary artery disease (CAD) is a major risk factor for death on dialysis. The objective of this study was to compare prevalent trends and patterns of survival in successive national cohorts.

METHODS

National data on 823,753 incident dialysis patients, aged 18 and over, were analyzed from the US Renal Data System from 1995 to 2004. The prevalence of CAD was compared across calendar years by sex and race categorized as; White, Black, Asian and Native American/Alaskan Native (Native Am). Two-year mortality rates were determined for annual cohorts and multivariable Cox regression compared hazard ratios (HR) and 95% confidence intervals.

RESULTS

From 1995 to 2004, the annual prevalence of CAD increased significantly in men from 25.2 to 30.1% and in women from 22.1 to 25.3%, p < 0.001. For men, the rise in prevalence was largely due to increases among Black men and older White men. For women, the pattern was similar. During this period, death rates decreased significantly from 379 to 348 and from 396 to 357 per 1,000 person-years in men and women respectively. Multivariate analysis identified significant reductions in mortality with advancing calendar year for White (HR 0.98 (0.98-0.99)), Asian (HR 0.93 (0.91-0.96)), and Native Am men (HR 0.95 (0.90-0.99)), and for White (HR 0.99 (0.98-0.99)) and Native Am women (HR 0.93 (0.89-0.98)). No significant trends were observed for Black patients.

CONCLUSIONS

Despite a rising burden of CAD among incident US dialysis patients, mortality rates have fallen for most groups. Substantial racial disparities remain.

Comparison of the performances of cardiac troponins, including sensitive assays, and copeptin in the diagnostic of acute myocardial infarction and long-term prognosis between women and men

BACKGROUND

Concerns have been raised about possible gender disparities in cardiac investigations and/or outcome. This study sought to examine and compare the diagnostic and prognostic performance of selected cardiac biomarkers in women versus men.

METHODS

In a prospective, multicenter cohort of patients with acute chest pain cardiac troponin T (cTnT) (fourth-generation Roche assay), high-sensitivity cTnT (hs-cTnT), and copeptin were measured at presentation.

RESULTS

Of 1,247 patients, 420 were women and 827 were men. Although the rate of acute myocardial infarction was similar in women (14.5%) and men (16.6%, P = .351), women more frequently had cardiac but noncoronary causes of chest pain (17.4% vs 10.8%, P = .001) and less frequently had unstable angina (8.8% vs 16.6%, P = .002) than men. Diagnostic accuracy as quantified by the area under the receiver operating characteristic curve (AUC) for acute myocardial infarction in women was 0.90 (95% CI 0.84-0.95) for cTnT, which was lower than the AUC for hs-cTnT alone (0.94, 95% CI [0.91-0.98]), the combination of cTnT with copeptin (0.96, 95% CI [0.94-0.98]) or the combination of hs-cTnT with copeptin (0.96, 95% CI [0.93-0.98]) (P = .008, P = .006, and P = .002, respectively). Prognostic accuracy as quantified by the AUCs for 1-year mortality was 0.69 (0.56-0.83), 0.86 (0.79-0.93), 0.87 (0.81-0.94), and 0.87 (0.80-0.94), respectively. No relevant gender differences in AUCs were observed.

CONCLUSION

The diagnostic and prognostic performance of cTnT, hs-cTnT, and copeptin is as good in women as in men. High-sensitivity cTnT and the combination of cTnT and copeptin outperform cTnT alone, both in women and men.

Hospital-level associations with 30-day patient mortality after cardiac surgery: a tutorial on the application and interpretation of marginal and multilevel logistic regression

Background

Marginal and multilevel logistic regression methods can estimate associations between hospital-level factors and patient-level 30-day mortality outcomes after cardiac surgery. However, it is not widely understood how the interpretation of hospital-level effects differs between these methods.

Methods

The Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) registry provided data on 32,354 patients undergoing cardiac surgery in 18 hospitals from 2001 to 2009. The logistic regression methods related 30-day mortality after surgery to hospital characteristics with concurrent adjustment for patient characteristics.

Results

Hospital-level mortality rates varied from 1.0% to 4.1% of patients. Ordinary, marginal and multilevel regression methods differed with regard to point estimates and conclusions on statistical significance for hospital-level risk factors; ordinary logistic regression giving inappropriately narrow confidence intervals. The median odds ratio, MOR, from the multilevel model was 1.2 whereas ORs for most patient-level characteristics were of greater magnitude suggesting that unexplained between-hospital variation was not as relevant as patient-level characteristics for understanding mortality rates. For hospital-level characteristics in the multilevel model, 80% interval ORs, IOR-80%, supplemented the usual ORs from the logistic regression. The IOR-80% was (0.8 to 1.8) for academic affiliation and (0.6 to 1.3) for the median annual number of cardiac surgery procedures. The width of these intervals reflected the unexplained variation between hospitals in mortality rates; the inclusion of one in each interval suggested an inability to add meaningfully to explaining variation in mortality rates.

Conclusions

Marginal and multilevel models take different approaches to account for correlation between patients within hospitals and they lead to different interpretations for hospital-level odds ratios.