Atherosclerotic Burden and Heart Failure After Myocardial Infarction

IMPORTANCE

Whether the extent of coronary artery disease (CAD) is associated with the occurrence of heart failure (HF) after myocardial infarction (MI) is not known. Furthermore, whether this association might differ by HF type according to preserved or reduced ejection fraction (EF) has yet to be determined.

OBJECTIVES

To evaluate in a community cohort of patients with incident (first-ever) MI the association of angiographic CAD with subsequent HF and to examine the prognostic role of CAD according to HF subtypes: HF with reduced EF and HF with preserved EF.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study was conducted in 1922 residents of Olmsted County, Minnesota, with incident MI diagnosed between January 1, 1990, and December 31, 2010, and no prior HF; study participants were followed up through March 31, 2013. The extent of angiographic CAD was determined at baseline and categorized according to the number of major epicardial coronary arteries with 50% or more lumen diameter obstruction.

MAIN OUTCOMES AND MEASURES

The primary end point was time to incident HF. The primary exposure variable was the extent of CAD as expressed by the number of major coronary arteries with significant obstruction (0-, 1-, 2-, or 3-vessel disease) obtained from coronary angiograms performed no more than 1 day after the MI. Heart failure was ascertained by the Framingham criteria and classified by type according to EF (50% cutoff).

RESULTS

Of the 1922 participants, 1258 (65.4%) were men (mean [SD] age, 64 [13] years). During a mean follow-up period of 6.7 (5.9) years, 588 patients (30.6%) developed HF. With death and recurrent MI modeled as competing risks, the cumulative incidence rates of post-MI HF among patients with 0 or 1, 2, and 3 diseased vessels were 10.7%, 14.6%, and 23.0% at 30 days; and 14.7%, 20.6%, and 29.8% at 5 years, respectively (P < .001 for trend). After adjustment for clinical characteristics in a Cox proportional hazards regression model, the hazard ratios (95% CIs) for HF were 1.25 (0.99-1.59) and 1.75 (1.40-2.20) in patients with 2 and 3 vessels vs 0 or 1 occluded vessel, respectively (P < .001 for trend). The increased risk with a greater number of occluded vessels was independent of the occurrence of a recurrent MI and did not differ appreciably by HF type.

CONCLUSIONS AND RELEVANCE

The extent of angiographic CAD is an indicator of post-MI HF regardless of HF type and independent of recurrent MI. These data underscore the need to further investigate the processes taking place in the transition from myocardial injury to HF.

Outcome and undertreatment of mitral regurgitation: a community cohort study

BACKGROUND

Mitral regurgitation is the most common valve disease worldwide but whether the community-wide prevalence, poor patient outcomes, and low rates of surgical treatment justify costly development of new therapeutic interventions remains uncertain. Therefore, we did an observational cohort study to assess the clinical characteristics, outcomes, and degree of undertreatment of mitral regurgitation in a community setting.

METHODS

We used data from Mayo Clinic electronic health records and the Rochester Epidemiology Project to identify all cases of moderate or severe isolated single-valvular mitral regurgitation (with no other severe left-sided valvular disease or previous mitral surgery) diagnosed during a 10-year period in the community setting in Olmsted County (MN, USA). We assessed clinical characteristics, mortality, heart failure incidence, and results of cardiac surgery post-diagnosis.

FINDINGS

Between Jan 1, 2000, and Dec 31, 2010, 1294 community residents (median age at diagnosis 77 years [IQR 66-84]) were diagnosed with moderate or severe mitral regurgitation by Doppler echocardiography (prevalence 0·46% [95% CI 0·42-0·49] overall; 0·59% [0·54-0·64] in adults). Left-ventricular ejection fraction below 50% was frequent (recorded in 538 [42%] patients), and these patients had a slightly lower regurgitant volume than those with an ejection fraction of 50% or higher (mean 39 mL [SD 16] vs 45 mL [21], p<0·0001). Post-diagnosis mortality was mainly cardiovascular in nature (in 420 [51%] of 824 patients for whom the cause of death was available) and higher than expected for residents of the county for age or sex (risk ratio [RR] 2·23 [95% CI 2·06-2·41], p<0·0001). This excess mortality affected all subsets of patients, whether they had a left-ventricular ejection fraction lower than 50% (RR 3·17 [95% CI 2·84-3·53], p<0·0001) or of 50% or higher (1·71 [1·53 -1·91], p<0·0001) and with primary mitral regurgitation (RR 1·73 [95% CI 1·53-1·96], p<0·0001) or secondary mitral regurgitation (2·72 [2·48-3·01], p<0·0001). Even patients with a low comorbidity burden combined with favourable characteristics such as left-ventricular ejection fraction of 50% or higher (RR 1·28 [95% CI 1·10-1·50], p<0·0017) or primary mitral regurgitation (1·29 [1·09-1·52], p=0·0030) incurred excess mortality. Heart failure was frequent (mean 64% [SE 1] at 5 years postdiagnosis), even in patients with left-ventricular ejection fraction of 50% or higher (49% [2] at 5 years postdiagnosis) or in those with primary mitral regurgitation (48% [2]). Mitral surgery was ultimately done in only 198 (15%) of 1294 patients, of which the predominant type of surgery was valve repair (in 149 [75%] patients). Mitral surgery was done in 28 (5%) of 538 patients with left-ventricular ejection fraction below 50% and in 170 (22%) of 756 patients with ejection fraction of 50% or higher, and in 34 (5%) of 723 with secondary mitral regurgitation versus 164 (29%) of 571 with primary regurgitation. All other types of cardiac surgery combined were performed in only 3% more patients (237 [18%] patients) than the number who underwent mitral surgery.

INTERPRETATION

In the community, isolated mitral regurgitation is common and is associated with excess mortality and frequent heart failure postdiagnosis in all patient subsets, even in those with normal left-ventricular ejection fraction and low comorbidity. Despite these poor outcomes, only a minority of affected patients undergo mitral (or any type of cardiac) surgery even in a community with all means of diagnosis and treatment readily available and accessible. This suggests that in a wider population there might be a substantial unmet need for treatment for this disorder.

FUNDING

Mayo Clinic Foundation.

Contemporary Risk Stratification After Myocardial Infarction in the Community: Performance of Scores and Incremental Value of Soluble Suppression of Tumorigenicity-2

BACKGROUND

Current American Heart Association/American College of Cardiology guidelines recommend the GRACE (Global Registry of Acute Coronary Events) and TIMI (Thrombolysis in Myocardial Infarction) scores to assess myocardial infarction (MI) prognosis. Changes in the epidemiological characteristics of MI and the availability of new biomarkers warrant an assessment of the performance of these scores in contemporary practice. We assessed the following: (1) the performance of GRACE and TIMI to predict 1-year mortality in a cohort of patients stratified by ST-segment elevation MI (STEMI) and non-STEMI (NSTEMI) and (2) the incremental discriminatory power of soluble suppression of tumorigenicity-2, a myocardial fibrosis biomarker.

METHODS AND RESULTS

Olmsted County, Minnesota, residents with incident MI (N=1401) were recruited prospectively from November 1, 2002 to December 31, 2012 (mean age, 67 years; 61% men; 79% with NSTEMI). Baseline data were used to calculate risk scores; soluble suppression of tumorigenicity-2 was measured in stored plasma samples obtained at index MI. C-statistics adapted to survival data were used to assess the discriminatory power of the risk scores and the improvement gained by adding other markers. During the first year of follow-up, 190 patients (14%) died. The discriminatory performance to predict death was reasonable for GRACE and poor for TIMI, and was generally worse in those with NSTEMI versus those with STEMI. In people with NSTEMI, sequential addition of comorbidities and soluble suppression of tumorigenicity-2 substantially improved the c-statistic over GRACE (from 0.78 to 0.80 to 0.84) and TIMI (from 0.61 to 0.73 to 0.81), respectively (all P≤0.05).

CONCLUSIONS

Guideline-recommended scores for risk assessment after MI underperform in contemporary community patients, particularly those with NSTEMI, which now represents most infarcts. Incorporating comorbidities and soluble suppression of tumorigenicity-2 substantially improves risk prediction, thereby delineating opportunities to improve clinical care.

Pathophysiology of Aortic Valve Stenosis: Is It Both Fibrocalcific and Sex Specific?

Our understanding of the fundamental biology and identification of efficacious therapeutic targets in aortic valve stenosis has lagged far behind the fields of atherosclerosis and heart failure. In this review, we highlight the most clinically relevant problems facing men and women with fibrocalcific aortic valve stenosis, discuss the fundamental biology underlying valve calcification and fibrosis, and identify key molecular points of intersection with sex hormone signaling.