The independent associations of anti-Müllerian hormone and estradiol levels over the menopause transition with lipids/lipoproteins: The Study of Women's health Across the Nation

BACKGROUND

The menopause transition (MT) is linked to adverse changes in lipids/lipoproteins. However, the related contributions of anti-Müllerian hormone (AMH) and estradiol (E2) are not clear.

OBJECTIVE

To evaluate the independent associations of premenopausal AMH and E2 levels and their changes with lipids/lipoproteins levels [total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-1)] over the MT.

METHODS

SWAN participants who transitioned to menopause without exogenous hormone use, hysterectomy, or bilateral oophorectomy with data available on both exposure and outcomes when they were premenopausal until the 1st visit postmenopausal were studied.

RESULTS

The study included 1,440 women (baseline-age:mean±SD=47.4±2.6) with data available from up to 9 visits (1997-2013). Lower premenopausal levels and greater declines in AMH were independently associated with greater TC and HDL-C, whereas lower premenopausal levels and greater declines in E2 were independently associated with greater TG and apo B and lower HDL-C. Greater declines in AMH were independently associated with greater apoA-1, and greater declines in E2 were independently associated with greater TC and LDL-C.

CONCLUSIONS

AMH and E2 and their changes over the MT relate differently to lipids/lipoproteins profile in women during midlife. Lower premenopausal and/or greater declines in E2 over the MT were associated with an atherogenic lipid/lipoprotein profile. On the other hand, lower premenopausal AMH and/or greater declines in AMH over the MT were linked to higher apo A-1 and HDL-C; the later found previously to be related to a greater atherosclerotic risk after menopause.

Is race or ethnicity associated with under-utilization of statins among women in the United States: The study of women's health across the nation

Background

Rates of statin use among minority women are unclear.

Hypothesis

We hypothesized that statin use would vary by race/ethnicity with lower rates among minority women compared with Whites.

Methods

Data from the study of women's health across the nation, a multiethnic cohort of women collected between 2009 to 2011 were used to examine reported statin use by race/ethnicity and risk profile. Multivariable logistic modeling was performed to estimate the odds ratio (OR) of statin treatment.

Results

Of the 2399 women included, 234 had a diagnosis of atherosclerotic disease (ASCVD), 254 were diabetic (without ASCVD), 163 had an LDL ≥190 mg/dL, and 151 had a 10 year ASCVD pooled risk score ≥7.5%. Statins were used by 49.6% of women with CVD; 59.8% of women with diabetes without known ASCVD; 42.3% of women with an LDL ≥190 mg/dL; and 19.9% of women with an ASCVD risk ≥7.5%. Rates of statin use were 43.8% for women with ≥ two prior ASCVD events and 69.4% for women with ≥ one prior ASCVD event plus multiple high‐risk conditions. Among women eligible for statins, Black women had a significantly reduced adjusted odds of being on a statin (OR 0.53, 95% confidence interval [CI] 0.36‐0.78) compared with White women.

Conclusions

In this cohort of multiethnic women, rates of statin use among women who would benefit were low, with Black women having lower odds of statin use than White women.

Healthy Lifestyle During the Midlife Is Prospectively Associated With Less Subclinical Carotid Atherosclerosis: The Study of Women's Health Across the Nation

Background

Measures of subclinical atherosclerosis are predictors of future cardiovascular outcomes as well as of physical and cognitive functioning. The menopausal transition is associated with accelerated progression of atherosclerosis in women. The prospective association between a healthy lifestyle during the midlife and subclinical atherosclerosis is unclear.

Methods and Results

Self‐reported data on smoking, diet, and physical activity from 1143 women in the Study of Women's Health Across the Nation were used to construct a 10‐year average Healthy Lifestyle Score (HLS) during the midlife. Markers of subclinical atherosclerosis were measured 14 years after baseline and included common carotid artery intima‐media thickness (CCA‐IMT), adventitial diameter (CCA‐AD), and carotid plaque. The associations of average HLS with CCA‐IMT and CCA‐AD were estimated using linear models; the association of average HLS with carotid plaque was estimated using cumulative logit models. Average HLS was associated with smaller CCA‐IMT and CCA‐AD in the fully adjusted models (P=0.0031 and <0.001, respectively). Compared with participants in the lowest HLS level, those in the highest level had 0.024 mm smaller CCA‐IMT (95% confidence interval: −0.048, 0.000), which equals 17% of the SD of CCA‐IMT, and 0.16 mm smaller CCA‐AD (95% confidence interval: −0.27, −0.04), which equals 24% of the SD of CCA‐AD. Among the 3 components of the HLS, abstinence from smoking had the strongest association with subclinical atherosclerosis.

Conclusions

Healthy lifestyle during the menopausal transition is associated with less subclinical atherosclerosis, highlighting the growing recognition that the midlife is a critical window for cardiovascular prevention in women.

Modifiable Risk Factors for Incident Heart Failure in Atrial Fibrillation

OBJECTIVES

This study sought to identify modifiable risk factors and estimate the impact of risk factor modification on heart failure (HF) risk in women with new-onset atrial fibrillation (AF).

BACKGROUND

Incident HF is the most common nonfatal event in patients with AF, although strategies for HF prevention are lacking.

METHODS

We assessed 34,736 participants in the Women's Health Study who were free of prevalent cardiovascular disease at baseline. Cox models with time-varying assessment of risk factors after AF diagnosis were used to identify significant modifiable risk factors for incident HF.

RESULTS

Over a median follow-up of 20.6 years, 1,495 women developed AF without prevalent HF. In multivariable models, new-onset AF was associated with an increased risk of HF (hazard ratio [HR]: 9.03; 95% confidence interval [CI]: 7.52 to 10.85). Once women with AF developed HF, all-cause (HR: 1.83; 95% CI: 1.37 to 2.45) and cardiovascular mortality (HR: 2.87; 95% CI: 1.70 to 4.85) increased. In time-updated, multivariable models accounting for changes in risk factors after AF diagnosis, systolic blood pressure >120 mm Hg, body mass index ≥30 kg/m², current tobacco use, and diabetes mellitus were each associated with incident HF. The combination of these 4 modifiable risk factors accounted for an estimated 62% (95% CI: 23% to 83%) of the population-attributable risk of HF. Compared with women with 3 or 4 risk factors, those who maintained or achieved optimal risk factor control had a progressive decreased risk of HF (HR for 2 risk factors: 0.60; 95% CI: 0.37 to 0.95; 1 risk factor: 0.40; 95% CI: 0.25 to 0.63; and 0 risk factors: 0.14; 95% CI: 0.07 to 0.29).

CONCLUSIONS

In women with new-onset AF, modifiable risk factors including obesity, hypertension, smoking, and diabetes accounted for the majority of the population risk of HF. Optimal levels of modifiable risk factors were associated with decreased HF risk. Prospective assessment of risk factor modification at the time of AF diagnosis may warrant future investigation.

Vitamin E supplementation and the risk of heart failure in women

BACKGROUND

Oxidative stress may contribute to the development of heart failure (HF); however, an increased risk of HF has been observed with antioxidant therapy in secondary prevention trials. No large clinical trials have addressed the role of antioxidant therapy in the primary prevention of HF.

METHODS AND RESULTS

We examined the effect of vitamin E and HF risk in 39 815 initially healthy women, aged at least 45 years at baseline, who were enrolled in the Women's Health Study, a randomized, double-blind, placebo-controlled trial of vitamin E (600 IU every other day). Over a median follow-up of 10.2 years, there were 220 incident HF events. In proportional hazards models, adjusting for age and randomized aspirin and beta carotene treatment, vitamin E assignment did not significantly affect HF risk (hazards ratio [HR], 0.93; 95% CI, 0.71-1.21; P=0.59). These results did not change with multivariate adjustment for other risk factors, including interim myocardial infarction. In a prespecified subgroup analysis, vitamin E was inversely related to developing HF with normal ejection fraction (≥50%) with HR 0.59 (95% CI, 0.38-0.92; P=0.02), but there was no statistically significant effect on the risk of developing systolic HF (HR, 1.26; 95% CI, 0.84-1.89; P=0.26).

CONCLUSIONS

In this population of apparently healthy women, vitamin E did not affect the overall risk of HF. The possible benefit on diastolic HF requires confirmation in larger populations.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000479.

Risk of death and cardiovascular events in initially healthy women with new-onset atrial fibrillation

CONTEXT

The risks associated with new-onset atrial fibrillation (AF) among middle-aged women and populations with a low comorbidity burden are poorly defined.

OBJECTIVES

To examine the association between incident AF and mortality in initially healthy women and to evaluate the influence of associated cardiovascular comorbidities on risk.

DESIGN, SETTING, AND PARTICIPANTS

Between 1993 and March 16, 2010, 34,722 women participating in the Women's Health Study underwent prospective follow-up. Participants were 95% white, older than 45 years (median, 53 [interquartile range {IQR}, 49-59] years), and free of AF and cardiovascular disease at baseline. Cox proportional hazards models with time-varying covariates were used to determine the risk of events among women with incident AF. Secondary analyses were performed among women with paroxysmal AF.

MAIN OUTCOME MEASURES

Primary outcomes included all-cause, cardiovascular, and noncardiovascular mortality. Secondary outcomes included stroke, congestive heart failure, and myocardial infarction.

RESULTS

During a median follow-up of 15.4 (IQR, 14.7-15.8) years, 1011 women developed AF. Incidence rates per 1000 person-years among women with and without AF were 10.8 (95% confidence interval [CI], 8.1-13.5) and 3.1 (95% CI, 2.9-3.2) for all-cause mortality, 4.3 (95% CI, 2.6-6.0) and 0.57 (95% CI, 0.5-0.6) for cardiovascular mortality, and 6.5 (95% CI, 4.4-8.6) and 2.5 (95% CI, 2.4-2.6) for noncardiovascular mortality, respectively. In multivariable models, hazard ratios (HRs) of new-onset AF for all-cause, cardiovascular, and noncardiovascular mortality were 2.14 (95% CI, 1.64-2.77), 4.18 (95% CI, 2.69-6.51), and 1.66 (95% CI, 1.19-2.30), respectively. Adjustment for nonfatal cardiovascular events potentially on the causal pathway to death attenuated these risks, but incident AF remained associated with all mortality components (all-cause: HR, 1.70 [95% CI, 1.30-2.22]; cardiovascular: HR, 2.57 [95% CI, 1.63-4.07]; and noncardiovascular: HR, 1.42 [95% CI, 1.02-1.98]). Among women with paroxysmal AF (n = 656), the increase in mortality risk was limited to cardiovascular causes (HR, 2.94; 95% CI, 1.55-5.59).

CONCLUSION

Among a group of healthy women, new-onset AF was independently associated with all-cause, cardiovascular, and noncardiovascular mortality, with some of the risk potentially explained by nonfatal cardiovascular events.

Incremental diagnostic value of regional left ventricular function over coronary assessment by cardiac computed tomography for the detection of acute coronary syndrome in patients with acute chest pain: from the ROMICAT trial

BACKGROUND

The incremental value of regional left ventricular function (LVF) over coronary assessment to detect acute coronary syndrome (ACS) is uncertain.

METHODS AND RESULTS

We analyzed 356 patients (mean age, 53+/-12 years; 62% men) with acute chest pain and inconclusive initial emergency department evaluation. Patients underwent 64-slice contrast-enhanced cardiac computed tomography before hospital admission. Caregivers and patients remained blinded to the results. Regional LVF and presence of coronary atherosclerotic plaque and significant stenosis (>50%) were separately assessed by 2 independent readers. Incremental value of regional LVF to predict ACS was determined in the entire cohort and in subgroups of patients with nonobstructive coronary artery disease, inconclusive assessment for stenosis (defined as inability to exclude significant stenosis due to calcium or motion), and significant stenosis. During their index hospitalization, 31 patients were ultimately diagnosed with ACS (8 myocardial infarction, 22 unstable angina), of which 74% (23 patients) had regional LV dysfunction. Adding regional LVF resulted in a 10% increase in sensitivity to detect ACS by cardiac computed tomography (87%; 95% confidence interval, 70% to 96%) and significantly improved the overall accuracy (c-statistic: 0.88 versus 0.94 and 0.79 versus 0.88, for extent of plaque and presence of stenosis, respectively; both P<0.03). The diagnostic accuracy of regional LVF for detection of ACS has 89% sensitivity and 86% specificity in patients with significant stenosis (n=33) and 60% sensitivity and 86% specificity in patients with inconclusive coronary computed tomographic angiography (n=33).

CONCLUSIONS

Regional LVF assessment at rest improves diagnostic accuracy for ACS in patients with acute chest pain, especially in those with coronary artery disease and thus may be helpful to guide further management in patients at intermediate risk for ACS.

Influence of blood pressure and blood pressure change on the risk of congestive heart failure in the elderly

BACKGROUND

While elevated blood pressure (BP) has been consistently associated with incident congestive heart failure (CHF), much less is known about the effect of BP change. We therefore assessed the association of BP change over time with subsequent risk of CHF.

METHODS

4655 participants >/=65 years old from the prospective Established Populations for Epidemiologic Studies of the Elderly program who were alive and free of CHF after six years of follow-up were included. Categories of sustained high BP, sustained low BP, BP progression and BP regression were defined according to BP differences between study entry and six years of follow-up. The primary endpoint was incident CHF subsequent to the six year examination.

RESULTS

During 4.3 years of follow-up after the six year examination, 642 events occurred. The hazard ratio (HR) (95% confidence interval (CI)) for systolic BP > or =160 compared to <120 mm Hg at six years was 1.39 (1.04-1.86). Conversely, the lowest diastolic BP category at six years was associated with an increased risk of incident CHF (HR (95% CI) <70 mm Hg versus 70-79 mm Hg 1.42 (1.18-1.71)). Systolic and diastolic BP were better predictors than pulse pressure. The HRs (95% CI) for incident CHF associated with sustained high systolic BP > or =160 mm Hg and systolic BP progression were 1.35 (0.97-1.89) and 1.45 (1.14-1.85), respectively. Conversely, significant associations were found in those with sustained low diastolic BP or diastolic BP regression (HR (95% CI) 1.42 (1.11-1.83) and 1.45 (1.19-1.76), respectively).

CONCLUSION

While persistently elevated systolic BP and systolic BP progression were strong predictors of CHF in the elderly, inverse associations were found with regard to diastolic BP. Systolic and diastolic BP were better predictors of CHF than pulse pressure.

Ethnic differences in C-reactive protein concentrations

BACKGROUND

Limited data exist regarding the ethnic differences in C-reactive protein (CRP) concentrations, an inflammatory marker associated with risk of cardiovascular disease (CVD). We hypothesized that known CVD risk factors, including anthropometric characteristics, would explain much of the observed ethnic variation in CRP.

METHODS

We performed a cross-sectional analysis of 3154 women, without known CVD and not receiving hormone therapy, enrolled in the Study of Women's Health Across the Nation (SWAN), a multiethnic prospective study of pre- and perimenopausal women.

RESULTS

The study population was 47.4% white, 27.7% African-American, 8.5% Hispanic, 7.7% Chinese, and 8.6% Japanese; mean age was 46.2 years. African-American women had the highest median CRP concentrations (3.2 mg/L), followed by Hispanic (2.3 mg/L), white (1.5 mg/L), Chinese (0.7 mg/L), and Japanese (0.5 mg/L) women (all pairwise P < 0.001 compared with white women). Body mass index (BMI) markedly attenuated the association between ethnicity and CRP. After adjusting for age, socioeconomic status, BMI, and other risk factors, African-American ethnicity was associated with CRP concentrations >3 mg/L (odds ratio 1.37, 95% CI 1.07-1.75), whereas Chinese and Japanese ethnicities were inversely related (0.58, 0.35-0.95, and 0.43, 0.26-0.72, respectively).

CONCLUSIONS

Modifiable risk factors, particularly BMI, account for much but not all of the ethnic differences in CRP concentrations. Further study is needed of these ethnic differences and their implications for the use of CRP in CVD risk prediction.

Measurement of the interleukin family member ST2 in patients with acute dyspnea: results from the PRIDE (Pro-Brain Natriuretic Peptide Investigation of Dyspnea in the Emergency Department) study

OBJECTIVES

The aim of this study was to examine the value of measurement of the interleukin-1 receptor family member ST2 in patients with dyspnea.

BACKGROUND

Concentrations of ST2 have been reported to be elevated in patients with heart failure (HF).

METHODS

Five hundred ninety-three dyspneic patients with and without acute destabilized HF presenting to an urban emergency department were evaluated with measurements of ST2 concentrations. Independent predictors of death at 1 year were identified.

RESULTS

Concentrations of ST2 were higher among those with acute HF compared with those without (0.50 vs. 0.15 ng/ml; p < 0.001), although amino-terminal pro-brain natriuretic peptide (NT-proBNP) was superior to ST2 for diagnosis of acute HF. Median concentrations of ST2 at presentation to the emergency department were higher among decedents than survivors at 1 year (1.08 vs. 0.18 ng/ml; p < 0.001), and in multivariable analyses, an ST2 concentration > or =0.20 ng/ml strongly predicted death at 1 year in dyspneic patients as a whole (HR = 5.6, 95% confidence interval [CI] 2.2 to 14.2; p < 0.001) as well as those with acute HF (hazard ratio [HR] = 9.3, 95% CI 1.3 to 17.8; p = 0.03). This risk associated with an elevated ST2 in dyspneic patients with and without HF appeared early and was sustained at 1 year after presentation (log-rank p value <0.001). A multi-marker approach with both ST2 and NT-proBNP levels identified subjects with the highest risk for death.

CONCLUSIONS

Among dyspneic patients with and without acute HF, ST2 concentrations are strongly predictive of mortality at 1 year and might be useful for prognostication when used alone or together with NT-proBNP.

Dietary intakes of flavonols and flavones and coronary heart disease in US women

Dietary flavonols and flavones are subgroups of flavonoids that have been suggested to decrease the risk of coronary heart disease (CHD). The authors prospectively evaluated intakes of flavonols and flavones in relation to risk of nonfatal myocardial infarction and fatal CHD in the Nurses' Health Study. They assessed dietary information from the study's 1990, 1994, and 1998 food frequency questionnaires and computed cumulative average intakes of flavonols and flavones. Cox proportional hazards regression with time-varying variables was used for analysis. During 12 years of follow-up (1990-2002), the authors documented 938 nonfatal myocardial infarctions and 324 CHD deaths among 66,360 women. They observed no association between flavonol or flavone intake and risk of nonfatal myocardial infarction or fatal CHD. However, a weak risk reduction for CHD death was found among women with a higher intake of kaempferol, an individual flavonol found primarily in broccoli and tea. Women in the highest quintile of kaempferol intake relative to those in the lowest had a multivariate relative risk of 0.66 (95% confidence interval: 0.48, 0.93; p for trend = 0.04). The lower risk associated with kaempferol intake was probably attributable to broccoli consumption. These prospective data do not support an inverse association between flavonol or flavone intake and CHD risk.

Association of atrial fibrillation and amino-terminal pro-brain natriuretic peptide concentrations in dyspneic subjects with and without acute heart failure: results from the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) study

BACKGROUND

Amino-terminal pro-brain natriuretic peptide (NT-proBNP) testing is useful for diagnosis or exclusion of heart failure (HF) in dyspneic patients. Atrial fibrillation (AF) may cause dyspnea in the absence of acute HF and may also affect plasma levels of NT-proBNP.

METHODS

We prospectively enrolled 599 patients presenting with dyspnea to the emergency department and obtained a blood sample for NT-proBNP measurement. The diagnosis of AF was identified via presentation electrocardiogram. A final diagnosis of HF was determined by blinded study physicians using all available hospital records for each subject through 60 days of follow-up. We assessed the association between the presence of AF and level of NT-proBNP in subsets of patients with and without HF.

RESULTS

Of 599 dyspneic patients, 75 (13%) were in AF at presentation; these patients had significantly higher median NT-proBNP levels when compared with those without AF (2934 vs 294 pg/mL, P < .0001). Among patients with acute HF, AF was present in 28%; NT-proBNP levels were lower in those with AF versus those without (3488 vs 4492 pg/mL, P < .001), but AF was not independently associated with NT-proBNP after multivariable adjustment. In patients without acute HF, median NT-proBNP concentrations were significantly higher in those with AF than in those without (932 vs 121 pg/mL, P = .02); in these subjects, AF was the strongest predictor of an NT-proBNP concentration in a range consistent with acute HF (odds ratio 9.94, 95% CI 2.97-33.3, P < .001).

CONCLUSION

Atrial fibrillation is associated with higher NT-proBNP concentrations in dyspneic patients, particularly in those without acute HF.

MDCT in Early Triage of Patients with Acute Chest Pain

OBJECTIVE

Current risk stratification of patients with acute chest pain but normal initial cardiac enzymes and nondiagnostic ECG is inefficient. We sought to determine whether contrast-enhanced MDCT-based detection of stenosis is feasible and improves early and accurate triage of patients with acute chest pain.

SUBJECTS AND METHODS

We studied 40 patients (53% men; mean age, 57 +/- 13 years) with chest pain who were awaiting hospital admission to rule out an acute coronary syndrome (ACS) despite the absence of diagnostic ECG changes and normal cardiac enzymes on emergency department presentation. Patients underwent contrast-enhanced MDCT before hospital admission. Afterward, patients received standard clinical care. All physicians involved in the patients' care were blinded to the results of MDCT. An expert panel established the presence or absence of ACS based on American Heart Association (AHA) guidelines. The MDCT images were evaluated for the presence of significant coronary artery stenosis (diameter reduction > 50%) and were used to make a triage decision.

RESULTS

All five patients (12.5%) with ACS (one with non-ST elevation myocardial infarction, four with unstable angina pectoris) had at least one significant coronary stenosis on MDCT (sensitivity, 100% [95% CI, 49-100%)]. ACS was ruled out in 35 patients (87.5%). Significant coronary stenosis was excluded in 26 of the 35 patients without ACS by MDCT (specificity, 74% [CI, 75-88%]), potentially saving 70% of unnecessary hospital admissions.

CONCLUSION

MDCT-based detection of significant coronary stenoses has tremendous potential to decrease the number of unnecessary hospital admissions, without reducing appropriate admission rates, in patients with chest pain who have nondiagnostic ECG results and normal cardiac enzymes. These results are likely to further improve with advances in MDCT technology.

Coronary multidetector computed tomography in the assessment of patients with acute chest pain

BACKGROUND

Noninvasive assessment of coronary atherosclerotic plaque and significant stenosis by coronary multidetector computed tomography (MDCT) may improve early and accurate triage of patients presenting with acute chest pain to the emergency department.

METHODS AND RESULTS

We conducted a blinded, prospective study in patients presenting with acute chest pain to the emergency department between May and July 2005 who were admitted to the hospital to rule out acute coronary syndrome (ACS) with no ischemic ECG changes and negative initial biomarkers. Contrast-enhanced 64-slice MDCT coronary angiography was performed immediately before admission, and data sets were evaluated for the presence of coronary atherosclerotic plaque and significant coronary artery stenosis. All providers were blinded to MDCT results. An expert panel, blinded to the MDCT data, determined the presence or absence of ACS on the basis of all data accrued during the index hospitalization and 5-month follow-up. Among 103 consecutive patients (40% female; mean age, 54+/-12 years), 14 patients had ACS. Both the absence of significant coronary artery stenosis (73 of 103 patients) and nonsignificant coronary atherosclerotic plaque (41 of 103 patients) accurately predicted the absence of ACS (negative predictive values, 100%). Multivariate logistic regression analyses demonstrated that adding the extent of plaque significantly improved the initial models containing only traditional risk factors or clinical estimates of the probability of ACS (c statistic, 0.73 to 0.89 and 0.61 to 0.86, respectively).

CONCLUSIONS

Noninvasive assessment of coronary artery disease by MDCT has good performance characteristics for ruling out ACS in subjects presenting with possible myocardial ischemia to the emergency department and may be useful for improving early triage.

Physical exertion, exercise, and sudden cardiac death in women

CONTEXT

Exercise is associated with a lower risk of cardiovascular events but may transiently increase the risk of ventricular arrhythmias. Its short-term and long-term associations with risk of sudden cardiac death among women are unclear.

OBJECTIVES

To compare the risk of sudden cardiac death in women during moderate to vigorous exertion with the risk of sudden cardiac death during lighter or no exertion; and to assess the long-term association between moderate to vigorous exercise and sudden cardiac death.

DESIGN, SETTING, AND PARTICIPANTS

Prospective, nested case-crossover study of 288 cases of sudden cardiac death within the Nurses' Health Study (1980-2004); and a prospective cohort analysis of 69,693 participants without prior cardiovascular disease followed up from 1986-2004.

MAIN OUTCOME MEASURE

Risk of sudden cardiac death associated with moderate to vigorous exertion.

RESULTS

The absolute risk of sudden cardiac death associated with moderate to vigorous exertion was exceedingly low at 1 per 36.5 million hours of exertion. In case-crossover analyses, the risk of sudden cardiac death was transiently elevated during moderate to vigorous exertion (relative risk [RR], 2.38; 95% confidence interval [CI], 1.23-4.60; P = .01) compared with the risk during lesser or no exertion. Habitual moderate to vigorous exertion modified this transient risk (P = .005 for interaction) and the risk was no longer significantly elevated among those who exercised 2 or more hours per week. In the cohort analyses, an increasing amount of moderate to vigorous exercise was associated with a lower long-term risk of sudden cardiac death in age-adjusted and multivariable models that excluded biological intermediates (P = .006 for trend). This relationship was attenuated when biological intermediates were included (P = .06 for trend); however, the reduction in risk remained significant among women who exercised 4 or more hours per week (adjusted RR, 0.41; 95% CI, 0.20-0.83; P = .01) compared with women who did not exercise.

CONCLUSIONS

These prospective data suggest that sudden cardiac death during exertion is an extremely rare event in women. Regular exercise may significantly minimize this small transient risk and may lower the overall long-term risk of sudden cardiac death.

Nonsteroidal antiinflammatory drugs, acetaminophen, and the risk of cardiovascular events

BACKGROUND

Although randomized trials of cyclooxygenase-2 (COX-2) inhibitors have shown increased cardiovascular risk, studies of nonselective, nonsteroidal antiinflammatory drugs (NSAIDs) and acetaminophen have been inconsistent.

METHODS AND RESULTS

We examined the influence of NSAIDs and acetaminophen on the risk of major cardiovascular events (nonfatal myocardial infarction, fatal coronary heart disease, nonfatal and fatal stroke) in a prospective cohort of 70,971 women, aged 44 to 69 years at baseline, free of known cardiovascular disease or cancer, who provided medication data biennially since 1990. During 12 years of follow-up, we confirmed 2041 major cardiovascular events. Women who reported occasional (1 to 21 d/mo) use of NSAIDs or acetaminophen did not experience a significant increase in the risk of cardiovascular events. However, after adjustment for cardiovascular risk factors, women who frequently (> or =22 d/mo) used NSAIDs had a relative risk (RR) for a cardiovascular event of 1.44 (95% CI, 1.27 to 1.65) compared with nonusers, whereas those who frequently consumed acetaminophen had a RR of 1.35 (95% CI, 1.14 to 1.59). The elevated risk associated with frequent NSAID use was particularly evident among current smokers (RR=1.82; 95% CI, 1.38 to 2.42) and was absent among never smokers (Pinteraction=0.02). Moreover, we observed significant dose-response relations: Compared with nonusers, the RRs for a cardiovascular event among women who used > or =15 tablets per week were 1.86 (95% CI, 1.27 to 2.73) for NSAIDs and 1.68 (95% CI, 1.10 to 2.58) for acetaminophen.

CONCLUSIONS

Use of NSAIDs or acetaminophen at high frequency or dose is associated with a significantly increased risk for major cardiovascular events, although more moderate use did not confer substantial risk.

Dietary alpha-linolenic acid intake and risk of sudden cardiac death and coronary heart disease

BACKGROUND

Alpha-linolenic acid, an intermediate-chain n-3 fatty acid found primarily in plants, may decrease the risk of fatal coronary heart disease (CHD) through a reduction in fatal ventricular arrhythmias and sudden cardiac death (SCD).

METHODS AND RESULTS

We prospectively examined the association between dietary intake of alpha-linolenic acid assessed via updated food-frequency questionnaires and the risk of SCD, other fatal CHD, and nonfatal myocardial infarction (MI) among 76,763 women participating in the Nurses' Health Study who were free from cancer and completed a dietary questionnaire at baseline in 1984. During 18 years of follow-up, we identified 206 SCDs, 641 other CHD deaths, and 1604 nonfatal MIs. After controlling for coronary risk factors and other fatty acids, including long-chain n-3 fatty acids, the intake of alpha-linolenic acid was inversely associated with the risk of SCD (P for trend, 0.02) but not with the risk of other fatal CHD or nonfatal MI. Compared with women in the lowest quintile of alpha-linolenic acid intake, those in the highest 2 quintiles had a 38% to 40% lower SCD risk. This inverse relation with SCD risk was linear and remained significant even among women with high intakes of long-chain n-3 fatty acids.

CONCLUSIONS

These prospective data suggest that increasing dietary intake of alpha-linolenic acid may reduce the risk of SCD but not other types of fatal CHD or nonfatal MI in women. The specificity of the association between alpha-linolenic acid and SCD supports the hypothesis that these n-3 fatty acids may have antiarrhythmic properties.

Utility of Amino-Terminal Pro–Brain Natriuretic Peptide Testing for Prediction of 1-Year Mortality in Patients With Dyspnea Treated in the Emergency Department

BACKGROUND

Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is useful for diagnosis and triage of patients with dyspnea, but its role for predicting outcomes in such patients remains undefined.

METHODS

A total of 599 breathless patients treated in the emergency department were prospectively enrolled, and a sample of blood was obtained for NT-proBNP measurements. After 1 year, the vital status of each patient was ascertained, and the association between NT-proBNP values at presentation and mortality was assessed.

RESULTS

At 1 year, 91 patients (15.2%) had died. Median NT-proBNP concentrations at presentation among decedents were significantly higher than those of survivors (3277 vs 299 pg/mL; P<.001). The optimal NT-proBNP cut point for predicting 1-year mortality was 986 pg/mL. In a multivariable model, an NT-proBNP concentration greater than 986 pg/mL at presentation was the single strongest predictor of death at 1 year (hazard ratio [HR], 2.88; 95% confidence interval, 1.64-5.06; P<.001), independent of a diagnosis of heart failure. Other factors associated with death included age (by decade; HR, 1.20), heart rate (by decile; HR, 1.13), urea nitrogen level (by decile; HR, 1.20), systolic blood pressure less than 100 mm Hg (HR, 1.94), heart murmur (HR, 1.92), and New York Heart Association classification (HR, 1.38 for each increase in class). The NT-proBNP concentration alone had an area under the receiver operating characteristic curve (AUC) of 0.76 for predicting mortality; the other significant covariates combined had an AUC of 0.80. The final model for predicting death, combining NT-proBNP with other covariates associated with mortality, had a superior AUC of 0.82.

CONCLUSION

In addition to assisting in emergency department diagnosis and triage, NT-proBNP concentrations at presentation are strongly predictive of 1-year mortality in dyspneic patients.

Aging syndrome genes and premature coronary artery disease

Background

Vascular disease is a feature of aging, and coronary vascular events are a major source of morbidity and mortality in rare premature aging syndromes. One such syndrome is caused by mutations in the lamin A/C (LMNA) gene, which also has been implicated in familial insulin resistance. A second gene related to premature aging in man and in murine models is the KLOTHO gene, a hypomorphic variant of which (KL-VS) is significantly more common in the first-degree relatives of patients with premature coronary artery disease (CAD). We evaluated whether common variants at the LMNA or KLOTHO genes are associated with rigorously defined premature CAD.

Methods

We identified 295 patients presenting with premature acute coronary syndromes confirmed by angiography. A control group of 145 patients with no evidence of CAD was recruited from outpatient referral clinics. Comprehensive haplotyping of the entire LMNA gene, including the promoter and untranslated regions, was performed using a combination of TaqMan^® probes and direct sequencing of 14 haplotype-tagging single nucleotide polymorphisms (SNPs). The KL-VS variant of the KLOTHO gene was typed using restriction digest of a PCR amplicon.

Results

Two SNPs that were not in Hardy Weinberg equilibrium were excluded from analysis. We observed no significant differences in allele, genotype or haplotype frequencies at the LMNA or KLOTHO loci between the two groups. In addition, there was no evidence of excess homozygosity at the LMNA locus.

Conclusion

Our data do not support the hypothesis that premature CAD is associated with common variants in the progeroid syndrome genes LMNA and KLOTHO.

Relation of lower hematocrit to progression from asymptomatic left ventricular dysfunction to symptomatic heart failure (from the Studies of Left Ventricular Dysfunction Prevention trial)

The relation between hematocrit and progression from asymptomatic left ventricular (LV) systolic dysfunction to symptomatic heart failure (HF) was examined in 2,821 patients from the Studies of Left Ventricular Dysfunction Prevention trial. Patients in the lowest hematocrit quartile (hematocrit < or = 40%) were at increased risk for the development of HF symptoms (hazard ratio [HR] 1.79, 95% confidence interval [CI] 1.37 to 2.34), first HF hospitalization (HR 2.35, 95% CI 1.52 to 3.62), and death or the development of HF symptoms (HR 1.60, 95% CI 1.28 to 1.99) compared with patients in the highest hematocrit quartile (hematocrit > 46%).

Ethnic variation in hypertension among premenopausal and perimenopausal women: Study of Women's Health Across the Nation

Data are sparse regarding hypertension prevalence, treatment, and control among some ethnic groups of American women. Furthermore, the effects of ethnicity on hypertension, independent of other factors that vary with ethnicity, are poorly understood. We examined the prevalence of hypertension (defined as systolic > or =140 or diastolic > or =90 mm Hg or receiving treatment), treatment, and control (to <140/<90 mm Hg) in a multiethnic study of premenopausal and perimenopausal women. Stepwise multivariable logistic regression was used to select covariates associated with hypertension. Among 3292 women, 46.9% were white, 28.3% were black, 8.7% were Hispanic, 7.6% were Chinese, and 8.5% were Japanese. Among these 5 ethnic groups, respectively, there was substantial variation in prevalence of normal blood pressure levels (<120/<80 mm Hg; 59.9%, 35.4%, 16.8%, 67.2%, and 63.7%) and hypertension (14.5%, 38.1%, 27.6%, 12.8%, and 11.0%). After multivariable adjustment, hypertension prevalence was 2 to 3x higher among black and Hispanic women but similar among Chinese and Japanese women compared with white women. Among hypertensive participants, prevalence of antihypertensive treatment was highest among blacks (58.9%) and whites (55.2%) and lowest among Chinese (34.4%). Prevalence of control to goal blood pressure levels was highest among whites (43.0%) and Japanese (38.7%) and markedly lower among Hispanic women (11.4%). Compared with whites, black and Hispanic women have significantly higher prevalence of hypertension independent of other factors, whereas Chinese and Japanese women have similar prevalence. Treatment and control rates vary considerably across ethnicities. Greater efforts must be made to improve hypertension awareness, treatment, and control in all middle-aged women, particularly those in ethnic minority groups.

Phobic anxiety and risk of coronary heart disease and sudden cardiac death among women

BACKGROUND

High levels of phobic anxiety have been associated with elevated risks of coronary heart disease (CHD) death and sudden cardiac death (SCD) among men. To the best of our knowledge, no studies have looked at this association among women. Anxiety may influence CHD mortality by increasing the risk of ventricular arrhythmia and SCD.

METHODS AND RESULTS

We prospectively examined the relationship between phobic anxiety, as measured by the Crown-Crisp index (CCI), and CHD among women participating in the Nurses' Health Study. Among 72,359 women with no history of cardiovascular disease or cancer in 1988, 97 SCDs, 267 CHD deaths, and 930 nonfatal myocardial infarctions (MI) were documented over 12 years of follow-up. A higher score on the CCI was associated with an increased risk of SCD and fatal CHD but not of nonfatal MI in age-adjusted (P, trend < or =0.008) and in multivariable models excluding possible biological intermediaries (P, trend < or =0.03). Multivariable adjustment appeared to attenuate the relations; women who scored 4 or greater on the CCI were at a 1.59-fold (95% CI, 0.97 to 2.60) marginally increased risk of SCD and a 1.31-fold (95% CI, 0.97 to 1.75) marginally increased risk of fatal CHD compared with those who scored 0 or 1. After control for possible intermediaries (hypertension, diabetes, and elevated cholesterol), a trend toward an increased risk persisted for SCD (P=0.06).

CONCLUSIONS

These prospective data suggest that high levels of phobic anxiety are associated with an increased risk of fatal CHD, particularly from SCD. Some but not all of this risk can be accounted for by CHD risk factors associated with phobic anxiety.

The N-terminal Pro-BNP investigation of dyspnea in the emergency department (PRIDE) study

The utility of aminoterminal pro-brain natriuretic peptide (NT-proBNP) testing in the emergency department to rule out acute congestive heart failure (CHF) and the optimal cutpoints for this use are not established. We conducted a prospective study of 600 patients who presented in the emergency department with dyspnea. The clinical diagnosis of acute CHF was determined by study physicians who were blinded to NT-proBNP results. The primary end point was a comparison of NT-proBNP results with the clinical assessment of the managing physician for identifying acute CHF. The median NT-proBNP level among 209 patients (35%) who had acute CHF was 4,054 versus 131 pg/ml among 390 patients (65%) who did not (p <0.001). NT-proBNP at cutpoints of >450 pg/ml for patients <50 years of age and >900 pg/ml for patients >or=50 years of age were highly sensitive and specific for the diagnosis of acute CHF (p <0.001). An NT-proBNP level <300 pg/ml was optimal for ruling out acute CHF, with a negative predictive value of 99%. Increased NT-proBNP was the strongest independent predictor of a final diagnosis of acute CHF (odds ratio 44, 95% confidence interval 21.0 to 91.0, p <0.0001). NT-proBNP testing alone was superior to clinical judgment alone for diagnosing acute CHF (p = 0.006); NT-proBNP plus clinical judgment was superior to NT-proBNP or clinical judgment alone. NT-proBNP measurement is a valuable addition to standard clinical assessment for the identification and exclusion of acute CHF in the emergency department setting.

Effect of body mass index on natriuretic peptide levels in patients with acute congestive heart failure: a ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) substudy

BACKGROUND

Obesity is associated with lower B-type natriuretic peptide (BNP) levels in healthy individuals and patients with chronic congestive heart failure (CHF). Neither the mechanism of natriuretic peptide suppression in the obese patient nor whether obesity affects natriuretic peptide levels among patients with acute CHF is known.

METHODS

The associations of amino-terminal pro-BNP (NT-proBNP), BNP, and body mass index (BMI) were examined in 204 subjects with acute CHF. Multivariable regression analyses were performed to identify factors independently related to NT-proBNP and BNP levels.

RESULTS

Across clinical strata of normal (<25 kg/m2), overweight (25-29.9 kg/m2), and obese (> or =30 kg/m2) patients, median NT-proBNP and BNP levels decreased with increasing BMI (both P values < .001). In multivariable analyses adjusting for covariates known to affect BNP levels, the inverse relationship between BMI and both NT-proBNP and BNP remained ( P < .05 for both). Using a cut point of 900 pg/mL, NT-proBNP was falsely negative in up to 10% of CHF cases in overweight patients (25-29.9 kg/m2) and 15% in obese patients (> or =30 kg/m2). Using the standard cut point of 100 pg/mL, BNP testing was falsely negative in 20% of CHF cases in both overweight and obese patients. The assays for NT-proBNP and BNP exhibited similar overall sensitivity for the diagnosis of CHF.

CONCLUSIONS

When adjusted for relevant covariates, compared with normal counterparts, overweight and obese patients with acute CHF have lower circulating NT-proBNP and BNP levels, suggesting a BMI-related defect in natriuretic peptide secretion. NT-proBNP fell below the diagnostic cutoff for CHF less often than BNP in overweight and obese individuals; however, when used as a diagnostic tool to identify CHF in such patients, both markers may have reduced sensitivity.

Mild renal insufficiency and risk of congestive heart failure in men and women > or =70 years of age

Mild renal insufficiency is increasingly recognized as an independent risk factor for cardiovascular disease. However, few data exist regarding its relation to risk of congestive heart failure (CHF), a major public health problem in the elderly. To determine if mild renal insufficiency is associated with risk of incident CHF in the elderly, we analyzed data from 3,618 participants in the prospective, community-based Established Populations for Epidemiologic Studies of the Elderly (EPESE), who had no known CHF and had serum creatinine levels measured from 1987 to 1989. Mean age of the study population was 78.3 +/- 5.4 years; 84% had creatinine values <1.5 mg/dl and 98% had creatinine values < or =2.0 mg/dl. Creatinine clearance (CrCl) was calculated using the Cockcroft-Gault equation. During 3.9 years of follow-up, 488 subjects developed incident CHF as defined by hospital discharge and death certificate data. In a multivariate proportional hazards model, CrCl was inversely associated with CHF risk (p value for trend <0.001). Those in the lowest quartile of CrCl (< or =36.9 ml/min) had a nearly twofold (hazards ratio [HR] 1.99, 95% confidence intervals [CI] 1.43 to 2.79) greater risk of incident CHF compared with those in the highest quartile (>57.4 ml/min). Renal insufficiency, defined as creatinine > or =1.5 mg/dl in men and > or =1.3 mg/dl in women, was also associated with increased CHF risk (multivariate HR 1.43, 95% CI 1.17 to 1.74). Thus, mild renal insufficiency was a strong independent predictor of CHF in this cohort, suggesting that serum creatinine may offer a readily accessible tool to identify elderly patients at risk for CHF.

Prospective study of sudden cardiac death among women in the United States

BACKGROUND

There are few data regarding the determinants of sudden cardiac death (SCD) in women, primarily because of their markedly lower rate of SCD compared with men. Nonetheless, existing data, although sparse, suggest possible gender differences in risk factors for SCD.

METHODS AND RESULTS

In this prospective cohort of 121 701 women aged 30 to 55 years at baseline, SCD was defined as death within 1 hour of symptom onset. From 1976 to 1998, 244 SCDs were identified. Although the risk of SCD increased markedly with age, the percentage of cardiac deaths that were sudden decreased. Most (69%) women who suffered a SCD had no history of cardiac disease before their death. However, almost all of the women who died suddenly (94%) had reported at least 1 coronary heart disease risk factor. Smoking, hypertension, and diabetes conferred markedly elevated (2.5- to 4.0-fold) risk of SCD, similar to that conferred by a history of nonfatal myocardial infarction (relative risk, 4.1; 95% confidence interval, 2.9 to 6.7). Family history of myocardial infarction before age 60 years and obesity were associated with moderate (1.6-fold) elevations in risk. With regard to mechanism, 88% of SCDs were classified as arrhythmic. In 76% of these, the first rhythm documented was ventricular tachycardia or ventricular fibrillation.

CONCLUSIONS

These prospective data suggest that, as in men, coronary heart disease risk factors predict risk of SCD in women and that SCD is usually an arrhythmic death. Therefore, prevention of atherosclerosis or ventricular arrhythmias may reduce the incidence of SCD in women.

Isolated Systolic Hypertension in the Elderly

Isolated systolic hypertension (ISH) is the predominant form of hypertension in persons older than 50 years, who represent the majority of individuals with hypertension. Systolic blood pressure (SBP) determines Joint National Committee blood pressure stage, and therefore the need for therapy, far more often than diastolic blood pressure (DBP). SBP consistently is associated with greater risk for overall mortality, coronary heart disease, stroke, congestive heart failure, renal failure, and other end points. In addition, clinicians are far less aggressive and less successful at controlling SBP compared with DBP. Thus, SBP should be acknowledged as the major criterion that determines diagnosis, staging, and therapeutic management in older individuals. Several recent large, randomized, placebo-controlled trials of drug therapy targeting ISH in the elderly have shown dramatic reductions in cardiovascular end points and mortality. The treatment of patients with ISH must occur within the framework of the larger goals associated with treatment of hypertension generally. Lifestyle modification, including salt restriction and increasing physical activity, may contribute to improvements in arterial compliance and control of ISH in particular. In clinical trials, most antihypertensive agents decrease SBP more than DBP. However, certain drug classes, such as angiotensin-converting enzyme inhibitors and nitrates, have advantageous properties that may make them particularly useful for the treatment of ISH.

Blood pressure and inflammation in apparently healthy men

Inflammation plays an important role in the development of atherosclerosis, but the specific stimuli governing cytokine release in atherogenesis are unknown. We examined the hypothesis that hypertension may increase the risk of atherosclerosis via proinflammatory effects. In a cross-sectional study involving 508 apparently healthy men, we studied the association between blood pressure and baseline plasma concentrations of 2 inflammatory markers, intercellular adhesion molecule-1 (sICAM-1) and interleukin-6 (IL-6). Increase in systolic blood pressure (SBP) (P=0.003), pulse pressure (PP) (P=0.019), and mean arterial pressure (P=0.014) was significantly associated with levels of sICAM-1. All of these measures of blood pressure, as well as diastolic blood pressure (DBP), were significantly associated with levels of IL-6 (all, P</=0.001). In multiple linear regression models controlled for age and other cardiac risk factors, SBP (7.6 ng/mL per 10 mm Hg, P=0.016) and PP (8.13 ng/mL per 10 mm Hg, P=0.038) were significantly associated with sICAM-1 levels, whereas SBP (0.11 pg/mL per 10 mm Hg, P<0.001), DBP (0.11 pg/mL per 10 mm Hg, P=0.008), PP (0.10 pg/mL per 10 mm Hg, P=0.009), and mean arterial pressure (0.15 pg/mL per 10 mm Hg, P<0.001) had similar strong relationships with log-transformed IL-6 levels. Therefore, in apparently healthy men, we observed significant graded relationships between blood pressure and levels of sICAM-1 as well as IL-6. These data suggest that increased blood pressure may be a stimulus for inflammation and that this is a possible mechanism underlying the well-established role of hypertension as a risk factor for atherosclerotic disease.

Elevation in serum troponin I predicts the benefit of tirofiban

BACKGROUND

Elevations in serum troponins among patients with acute coronary syndromes have been shown to identify those patients who are at high risk for poor outcome and who accrue larger relative benefits from aggressive antiplatelet and antithrombotic therapies. We studied a group of patients from the PRISM-PLUS trial to explore whether simply using serum troponin I, a serum marker of cardiac injury, could predict benefit of GP IIb/IIIa receptor antagonism with tirofiban.

METHODS AND RESULTS

For this study, the subjects consisted of 55 patients receiving the combination therapy of tirofiban/heparin, and 55 receiving heparin alone. The baseline characteristics were similar between the two treatment groups. Serial blood samples were obtained over the first 24-hour period following randomization to study drug, and were analyzed for troponin I (TnI) levels. Among those patients with elevated serum TnI (>0.5 ng/ml), the 30-day event rate for death or myocardial infarction (MI) was reduced from 20.6% among the heparin only group to 3.6% for those treated with the combination of tirofiban/heparin, an absolute risk reduction of 17% and relative risk reduction of 83% (p=0.06). Among the TnI negative patients, the rates of death/MI at 30 days were 9.5% and 11.1% among the combination and heparin treated groups respectively (p=NS).

CONCLUSION

Irrespective of high-risk clinical factors, including ST segment depression, these data support the hypothesis that serum troponins identify those who benefit from aggressive antiplatelet therapy with tirofiban.

Diabetes and all-cause and coronary heart disease mortality among US male physicians

BACKGROUND

While diabetes has long been associated with increased risk of coronary heart disease (CHD), the magnitude of risk of diabetes-related CHD is uncertain.

OBJECTIVE

To evaluate the impact of diabetes and prior CHD on all-cause and CHD mortality.

METHODS

In a prospective cohort study of 91 285 US male physicians aged 40 to 84 years, participants were divided into 4 groups: (1) a reference group of 82 247 men free of both diabetes and CHD (previous myocardial infarction and/or angina) at baseline, (2) 2317 men with a history of diabetes but not CHD, (3) 5906 men with a history of CHD but not diabetes, and (4) 815 men with a history of both diabetes and CHD. Rates of all-cause and CHD mortality were compared in these groups.

RESULTS

Over 5 years (49 7952 person-years of follow-up), 3627 deaths from all causes were documented, including 1242 deaths from CHD. Compared with men with no diabetes or CHD, the age-adjusted relative risk of death from any cause was 2.3 (95% confidence interval [CI], 2.0-2.6) among men with diabetes and without CHD, 2.2 (95% CI, 2.0-2.4) among men with CHD and without diabetes, and 4.7 (95% CI, 4.0-5.4) among men with both diabetes and CHD. The relative risk of CHD death was 3.3 (95% CI, 2.6-4.1) among men with diabetes and without CHD, 5.6 (95% CI, 4.9-6.3) among men with CHD and without diabetes, and 12.0 (95% CI, 9.9-14.6) among men with both diabetes and CHD. Multivariate adjustment for body mass index, smoking status, alcohol intake, and physical activity as well as stratification by these variables did not materially alter these associations.

CONCLUSIONS

These prospective data indicate that diabetes is associated with a substantial increase in all-cause and CHD mortality. For all-cause mortality, the magnitude of excess risk conferred by diabetes is similar to that conferred by a history of CHD; for mortality from CHD, a history of CHD is a more potent predictor of death. The presence of both diabetes and CHD, however, identifies a particularly high-risk group.

Triggering of sudden death from cardiac causes by vigorous exertion

BACKGROUND

Retrospective and cross-sectional data suggest that vigorous exertion can trigger cardiac arrest or sudden death and that habitual exercise may diminish this risk. However, the role of physical activity in precipitating or preventing sudden death has not been assessed prospectively in a large number of subjects.

METHODS

We used a prospective, nested case-crossover design within the Physicians' Health Study to compare the risk of sudden death during and up to 30 minutes after an episode of vigorous exertion with that during periods of lighter exertion or none. We then evaluated whether habitual vigorous exercise modified the risk of sudden death that was associated with vigorous exertion. In addition, the relation of vigorous exercise to the overall risk of sudden death and nonsudden death from coronary heart disease was assessed.

RESULTS

During 12 years of follow-up, 122 sudden deaths were confirmed among the 21,481 male physicians who were initially free of self-reported cardiovascular disease and who provided information on their habitual level of exercise at base line. The relative risk of-sudden death during and up to 30 minutes after vigorous exertion was 16.9 (95 percent confidence interval, 10.5 to 27.0; P<0.001). However, the absolute risk of sudden death during any particular episode of vigorous exertion was extremely low (1 sudden death per 1.51 million episodes of exertion). Habitual vigorous exercise attenuated the relative risk of sudden death that was associated with an episode of vigorous exertion (P value for trend=0.006). The base-line level of exercise was not associated with the overall risk of subsequent sudden death.

CONCLUSIONS

These prospective data from a study of U.S. male physicians suggest that habitual vigorous exercise diminishes the risk of sudden death during vigorous exertion.

Pulse pressure and mortality in older people

BACKGROUND

In older people, observational data are unclear concerning the relationships of systolic and diastolic blood pressure with cardiovascular and total mortality. We examined which combinations of systolic, diastolic, pulse, and mean arterial pressure best predict total and cardiovascular mortality in older adults.

METHODS

In 1981, the National Institute on Aging initiated its population-based Established Populations for Epidemiologic Studies of the Elderly in 3 communities. At baseline, 9431 participants, aged 65 to 102 years, had blood pressure measurements, along with measures of medical history, use of medications, disability, and physical function. During an average follow-up of 10. 6 years among survivors, 4528 participants died, 2304 of cardiovascular causes.

RESULTS

In age- and sex-adjusted survival analyses, the lowest overall death rate occurred among those with systolic pressure less than 130 mm Hg and diastolic pressure 80 to 89 mm Hg; relative to this group, the highest death rate occurred in those with systolic pressure of 160 mm Hg or more and diastolic pressure less than 70 mm Hg (relative risk, 1.90; 95% confidence interval, 1.47-2.46). Both low diastolic pressure and elevated systolic pressure independently predicted increases in cardiovascular (P<.001) and total (P<.001) mortality. Pulse pressure correlated strongly with systolic pressure (R = 0.82) but was a slightly stronger predictor of both cardiovascular and total mortality. In a model containing pulse pressure and other potentially confounding variables, diastolic pressure (P =.88) and mean arterial pressure (P =.11) had no significant association with mortality.

CONCLUSIONS

Pulse pressure appears to be the best single measure of blood pressure in predicting mortality in older people and helps explain apparently discrepant results for low diastolic blood pressure.

Effects of tirofiban plus heparin versus heparin alone on troponin I levels in patients with acute coronary syndromes

Elevated serum troponins following an acute coronary syndrome (ACS) predict a poor clinical outcome. Glycoprotein (GP) IIb/IIIa inhibitors reduce adverse clinical outcomes in patients with ACS, although their effect on serum troponin I (TnI) in this setting has not been described. We therefore studied the effects of the GP IIb/IIIa inhibitor tirofiban on serum TnI levels in a group of patients in the Platelet Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms trial. Serial blood samples were obtained in 53 patients receiving the combination therapy of tirofiban/heparin and in 52 receiving heparin alone, and were analyzed for baseline, peak, and mean concentrations of TnI. Baseline TnI levels were not different between the combination therapy and heparin-only groups (1.6 +/- 3.0 vs 3.1 +/- 6.7 ng/ml, p = 0.15). The peak TnI level was significantly lower in the combination therapy group than in the heparin group (5.2 +/- 8.3 vs 15.5 +/- 29.1 ng/ml, p = 0.017), and mean levels over the initial 24-hour period were also significantly lower in the combination therapy group (3.2 +/- 5.0 vs 8.5 +/- 14.8 ng/ml, p = 0.016). In univariate analysis, combination therapy was associated with lower TnI levels, whereas in a multivariate model, the lower peak and mean TnI levels as a consequence of tirofiban/heparin compared with heparin monotherapy remained significant (peak, p = 0.029; mean, p = 0.035). Among patients with negative TnI at baseline, treatment with the combination of tirofiban/heparin compared with heparin monotherapy still resulted in significantly lower peak (2.5 +/- 5.4 vs 14.6 +/- 32.8 ng/ml, p = 0.024) and mean (1.2 +/- 2.6 vs 6.9 +/- 15.8 ng/ml, p = 0.029) TnI levels. In patients with ACS, therapy with the combination of tirofiban and heparin (compared with heparin treatment alone) resulted in lower serum TnI levels, suggesting reduced myocardial injury.

Male pattern baldness and coronary heart disease: the Physicians' Health Study

OBJECTIVE

To examine the association between male pattern baldness and the risk of coronary heart disease (CHD) events.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study among 22,071 US male physicians aged 40 to 84 years enrolled in the Physicians' Health Study. Of these, 19,112 were free of CHD at baseline and completed a questionnaire at the 11-year follow-up concerning their pattern of hair loss at age 45 years. Response options included no hair loss, frontal baldness only, or frontal baldness with mild, moderate, or severe vertex baldness.

MAIN OUTCOME MEASURES

Coronary heart disease events defined as nonfatal myocardial infarction (MI), angina pectoris, and/or coronary revascularization.

RESULTS

During 11 years of follow-up, we documented 1446 CHD events in this cohort. Compared with men with no hair loss, those with frontal baldness had an age-adjusted relative risk (RR) of CHD of 1.09 (95% confidence interval [CI], 0.94-1.25), while those with mild, moderate, or severe vertex baldness had RRs of 1.23 (95% CI, 1.05-1.43), 1.32 (95% CI, 1.10-1.59), and 1.36 (95% CI, 1.11-1.67), respectively (P for trend, <.001). Multivariate adjustment for age, parental history of MI, height, body mass index (weight in kilograms divided by the square of the height in meters as a continuous variable), smoking, history of hypertension, diabetes, high cholesterol level, physical activity, and alcohol intake did not materially alter these associations. Results were similar when nonfatal MI, angina, and coronary revascularization were examined separately, and when events were analyzed among men older and younger than 55 years at baseline. Vertex baldness was more strongly associated with CHD risk among men with hypertension (multivariate RR, 1.79; 95% CI, 1.31-2.44) or high cholesterol levels (multivariate RR, 2.78; 95% CI, 1.09-7.12).

CONCLUSION

Vertex pattern baldness appears to be a marker for increased risk of CHD events, especially among men with hypertension or high cholesterol levels.

Increased pulse pressure and risk of heart failure in the elderly

CONTEXT

Arterial stiffness increases with age. Thus, pulse pressure, an index of arterial stiffening, may predict congestive heart failure (CHF) in the elderly.

OBJECTIVE

To study prospectively the association between pulse pressure and risk of CHF.

DESIGN

Prospective cohort study.

SETTING

The community-based East Boston Senior Health Project, East Boston, Mass.

PATIENTS

A total of 1621 men and women (mean [SD] age, 77.9 [5.0] years) free of CHF who had blood pressure measurements taken in 1988-1989 and were followed up for 3.8 years.

MAIN OUTCOME MEASURE

Incidence of CHF as ascertained by hospital discharge diagnosis (n = 208) and death certificates (n = 13).

RESULTS

After controlling for age, sex, mean arterial pressure, history of coronary heart disease, diabetes mellitus, atrial fibrillation, valvular heart disease, and antihypertensive medication use, pulse pressure was an independent predictor of CHF. For each 10-mm Hg elevation in pulse pressure, there was a 14% increase in risk of CHF (95% confidence interval, 1.05-1.24; P = .003). Those in the highest tertile of pulse pressure (>67 mm Hg) had a 55% increased risk of CHF (P=.02) compared with those in the lowest (<54 mm Hg). Pulse pressure was more predictive than systolic blood pressure alone and was independent of diastolic blood pressure.

CONCLUSION

Pulse pressure, an easily measurable correlate of pulsatile hemodynamic load, is an independent predictor of risk of CHF in this elderly cohort.

Postmenopausal hormone replacement therapy and cardiovascular disease

Cardiovascular disease is the leading cause of mortality in postmenopausal women in developed countries. A possible cardioprotective role of hormone replacement therapy (HRT) is suggested by epidemiologic studies of HRT and reduced risk of coronary heart disease, as well as by randomized trials of HRT and lipid subfractions. Estrogen has beneficial effects on the lipid profile, raising high-density lipoprotein cholesterol levels and reducing low-density lipoprotein cholesterol levels each by approximately 10%. Other possible biologic mechanisms include beneficial effects on vascular function, oxidative status, endothelial-dependent vasodilation, intimal hyperplasia and insulin sensitivity. Estrogen's net effects on coagulation and fibrinolysis are less clear. Estrogen replacement therapy is associated with decreased atherosclerosis in several animal models. However, most of the available data on HRT derive from observational studies or small randomized trials assessing biologic intermediates rather than clinical events. Further research, including large-scale randomized clinical trials, are required to evaluate definitively the role of estrogen replacement therapy, especially given uncertainties about the effects of combined estrogen-progestin therapy and the balance of benefits and risk of this common intervention in postmenopausal women.

Degradation of collagen in lung tissue slices exposed to hyperoxia

Exposure of animals to oxidant gases produces a mild emphysema, and O2-derived free radicals are capable of degrading connective tissues in vitro. It is postulated that degradation of connective tissue by O2-derived free radicals leads to emphysema in these models. To determine whether exposure of lung tissue slices to an oxidant gas results in degradation of collagen and to investigate factors mediating this degradation, we exposed lung tissue slices from normal rats to hyperoxia (95% O2, 5% CO2) and measured hydroxyproline release into the medium. After a 4-h exposure, the hydroxyproline released was 5.3 +/- 0.2 micrograms/g lung tissue (n = 10) in normoxia and 8.1 +/- 0.6 micrograms/g tissue (n = 13) in hyperoxia (p less than 0.05), suggesting degradation of collagen. The addition of 0.1% trypsin to the initial incubation medium caused a synergistic increase in hydroxyproline release from O2-exposed slices: normoxia/trypsin, 46.2 +/- 3.6 micrograms/g tissue (n = 10); hyperoxia/trypsin, 61.4 +/- 3.6 micrograms/g tissue (n = 11) (p less than 0.05). The addition of proteinase inhibitors completely suppressed the O2-induced release of hydroxyproline, suggesting that proteolytic enzymes are involved in hyperoxia-mediated degradation of lung collagen.

Damage and repair of lung connective tissue in rats exposed to toxic levels of oxygen

We studied damage and repair of lung connective tissue in rats exposed to toxic amounts of oxygen by measuring lung content of collagen and elastin and the number of collagen fragments in lung lavage fluid after exposure to 98% O2 for 60 h. Lung collagen was decreased 17%, and collagen fragments in lavage fluid were increased 4- to 5-fold in O2-exposed rats compared with those in control rats. No biochemical evidence of elastin degradation was found. Mild emphysematous changes and a leftward shift of fluid-filled, pressure-volume curves were induced within 2 wk after recovery from exposure to O2. Administration of the lathyrogen beta-aminopropionitrile worsened the emphysematous lesion produced by hyperoxia, suggesting that replacement of connective tissue during repair limits the extent of emphysema. We conclude that lung collagen is degraded and an emphysematous lesion is produced by relatively short exposure to toxic amounts of oxygen.