Chronic respiratory illness as a predictor of survival in idiopathic dilated cardiomyopathy: the Washington, DC, Dilated Cardiomyopathy Study.

Although bronchial asthma and emphysema have been associated with idiopathic dilated cardiomyopathy in case-control studies, little is known about the prognostic importance of chronic respiratory disease in idiopathic dilated cardiomyopathy. To study this, we examined history of bronchial asthma, emphysema and chronic bronchitis, and respiratory medication use as possible predictors of survival in idiopathic dilated cardiomyopathy using data from a Washington, DC, population-based study (n = 129). The cumulative survival rates among patients with a history of emphysema or chronic bronchitis were 60% and 48% at 12 and 36 months, respectively, compared with 81.8% and 67.2% among patients without emphysema or chronic bronchitis. The survival rates of idiopathic dilated cardiomyopathy patients with and without a history of bronchial asthma at the time of idiopathic dilated cardiomyopathy diagnosis were similar. In multivariate analysis using the proportional hazards model, only ventricular arrhythmias and ejection fraction were found to be statistically significant predictors of survival in idiopathic dilated cardiomyopathy. The adjusted relative risk estimate for emphysema and chronic bronchitis was close to one. Thus, the results of this population-based study do not suggest that history of chronic respiratory illness is an independent predictor of survival in idiopathic dilated cardiomyopathy.

Comparison of fourth and fifth Korotkoff diastolic blood pressures in 5 to 30 year old individuals. The Bogalusa Heart Study.

The use of fourth phase Korotkoff sound (K4) versus fifth phase Korotkoff sound (K5) for the determination of diastolic blood pressure (DBP) has been a subject of controversy since the indirect method of determining arterial blood pressure was described. Using data from the Bogalusa Heart Study, we evaluated the differences between K4 and K5 (K4-K5) from 4633 subjects 5 to 30 years of age examined between 1987 and 1991. The overall mean difference between K4 and K5 was 9.9 +/- 5.6 mm Hg (mean +/- SD). The average difference was highest in 5 to 8 year olds, where it measured 12.3 +/- 5.5 mm Hg. The average K4-K5 difference fell with increasing age and reached a value of 6.3 +/- 2.6 mm Hg by 25 years of age. For all race/sex groups, the youngest two age groups differed statistically from the oldest age groups in K4-K5 difference (P < .006). There were significant differences between blacks and whites (P < .015) and between men and women (P < .001) for subjects between 13 and 17 years of age. Additional analyses were performed with individuals having K5 = 0 added to yield an expanded population of 5117 persons. Overall, 9.5% had at least one of six measurements of K5 = 0 and most were young subjects: 27% of children 5 to 8 years and 13% of children 9 to 12 years. We conclude that by age 15 there may be no relevant clinical difference in K4-K5. However, in children, K4 and K5 should be recorded and K4 is a more reproducible measure of diastolic blood pressure.

Relation of blood pressure and body build to left ventricular mass in normotensive and hypertensive employed adults.

Left ventricular muscle mass is increased in the presence of large body size, high blood pressure and obesity, but the relative contributions to ventricular mass of these and other factors have not been elucidated. Accordingly, echocardiographic left ventricular mass in unmedicated employed adults (162 normotensive, 145 borderline hypertension and 317 with established essential hypertension) was related to height, weight, lean body mass, body mass index, systolic and diastolic blood pressure, age, gender, race and 24 h urinary sodium and potassium excretion. In the total population, body mass index, systolic blood pressure and height were the most significant (p less than 0.0001) independent correlates of left ventricular mass, whereas gender and age made smaller contributions. In each normotensive and hypertensive subgroup, body mass index and height remained highly significant independent predictors of left ventricular mass, systolic blood pressure became a weaker predictor (0.001 less than p less than 0.02) and only among patients with established hypertension was diastolic blood pressure a weak independent determinant (p less than 0.05) of ventricular mass. The increase in left ventricular mass attributable to obesity was due to eccentric hypertrophy because end-diastolic relative wall thickness was similar in obese and nonobese subjects in each blood pressure group. Thus obesity, as measured by body mass index, is as important a potential determinant of left ventricular muscle mass as is systolic blood pressure and it is of greater statistical significant in an adult employed population than is diastolic blood pressure, height, gender, age or dietary sodium intake.

Echocardiographic detection of pressure-overload left ventricular hypertrophy: effect of criteria and patient population.

To evaluate the performance of M-mode echocardiography for detection of pressure-overload left ventricular hypertrophy (LVH), we tested the sensitivity of previously defined sex-specific upper limits of normal echo LV measurements in 31 patients with necropsy-proven pressure-overload LVH and determined the prevalence of LVH detected by each echo criterion in 316 employed patients with uncomplicated hypertension, 100 patients with hypertension evaluated in a referral center, and 38 hospital patients with moderate to severe (WHO class 2) hypertension. Echo measurements were LV mass (LVM), LVM index (LVMI), cross-sectional area (CSA), septal and posterior wall thickness (IVST and PWT), LV internal dimension (LVID), and relative wall thickness (RWT). Prevalences of echo LVH were as follows. (Table: see text). Thus, echo criteria based on LVM are more sensitive than other measurements for detection of necropsy-proven pressure-overload LVH and reveal the highest prevalence of LVH in clinical hypertension populations, and the prevalence of LVH in hypertension is highly dependent on the population studied.

Cost-effectiveness of echocardiography and electrocardiography for detection of left ventricular hypertrophy in patients with systemic hypertension.

Although echocardiography is more accurate than electrocardiography for detection of left ventricular hypertrophy, it is also more expensive, making it uncertain whether echocardiography is cost-effective for detection of this abnormality in hypertensive patients. Accordingly, the sensitivity of M-mode echocardiographic and electrocardiographic criteria for left ventricular hypertrophy was determined in necropsied patients with anatomic hypertrophy of mild (n = 26), moderate (n = 21) or severe (n = 46) degree, and the prevalence of each degree of hypertrophy was determined in 561 hypertensive adults drawn from clinical and employed population samples. The sensitivity of echocardiographic left ventricular mass index criteria was 57% in necropsied patients with mild hypertrophy and 98% in patients with moderate or severe hypertrophy. All electrocardiographic criteria exhibited lower sensitivity: 15 to 42% for mild, 10 to 38% for moderate, and 30 to 57% for severe hypertrophy. Cost estimates from three sources were $160 for M-mode echocardiography and $48 to $64 for 12-lead electrocardiography. In populations with a 12 to 40% prevalence of hypertrophy, echocardiography was calculated to cost less than electrocardiography per instance of hypertrophy detected ($390-$1013 vs $800-$1829), yielded better separation in predicted incidence of morbid events between hypertensive patients with or without hypertrophy (3.4-4.7 vs 1.5-2.1 per 100 patient-years as opposed to 3.0-4.4 vs 1.9-2.9 per 100 patient-years), and required smaller case and control samples for hypothetical research studies (n = 254-309 vs 397-3478).(ABSTRACT TRUNCATED AT 250 WORDS)

Complications of mitral valve prolapse. Disproportionate occurrence in men and older patients.

To determine factors influencing the strength of association between mitral valve prolapse and mitral regurgitation, ruptured chordae tendineae, and infective endocarditis, the prevalence of mitral prolapse in patients with disease was compared with both clinical and population control groups. The prevalence of mitral valve prolapse was 4 percent among population and clinical control groups (eight of 196 and 84 of 2,146, respectively) and was significantly higher (p less than 0.001) in patients with endocarditis (11 of 67, 16 percent), mitral regurgitation (17 of 31, 55 percent, and ruptured chordae (27 of 43, 63 percent). Odds ratios for complications in persons with mitral valve prolapse ranged from 4.6 for endocarditis to 41.4 for ruptured chordae in overall analyses, and from 6.8 for endocarditis to 53.0 for ruptured chordae based on age- and sex-matched case-control triplets (p less than 0.001 for each). All complications occurred disproportionately in men with mitral valve prolapse, in whom odds ratios ranged from 2.5 to 7.4 compared with an additional control group of unselected subjects with mitral valve prolapse. Compared with this control group, patients with mitral valve prolapse and endocarditis were slightly more likely to have a previously known heart murmur (odds ratio 3.2, difference not significant) but significantly more likely to have murmurs at the time of evaluation (odds ratio 8.5, p less than 0.01). Patients with mitral valve prolapse and mitral regurgitation and ruptured chordae tendineae were also significantly older than the unselected subjects with mitral valve prolapse (48 +/- 14 and 55 +/- 16 versus 38 +/- 14 years, p less than 0.005 for both). The concentration of risk of endocarditis in men with mitral valve prolapse and patients with antecedent murmur suggests that antibiotic prophylaxis is warranted in these groups but not in women without a murmur of mitral regurgitation.

The prevalence and correlates of echocardiographic left ventricular hypertrophy among employed patients with uncomplicated hypertension.

To determine the prevalence and correlates of echocardiographic left ventricular hypertrophy among subjects in a general population, we studied 621 employed subjects. Patients with uncomplicated essential hypertension in a worksite-based treatment program included 145 with borderline hypertension and 316 with sustained hypertension by World Health Organization criteria. Normotensive subjects were randomly selected from members of the same unions. M-mode echocardiographic left ventricular dimensions were used to calculate left ventricular mass and other indexes of left ventricular anatomy. The specificity of 13 echocardiographic criteria of left ventricular hypertrophy was determined in normotensive individuals, and the prevalence of left ventricular hypertrophy by each criterion was assessed in patients with borderline or sustained essential hypertension. The results suggest that the most suitable reference standard for detection of left ventricular hypertrophy in a heterogeneous urban population utilizes sex-specific cutoff values for left ventricular mass index of 110 g/m2 or greater for women and 134 g/m2 or greater for men. With 97% specificity, the prevalence of left ventricular hypertrophy by these criteria is approximately 12% among patients with borderline hypertension and 20% among patients with relatively mild, uncomplicated sustained essential hypertension. Wall thickness measurements performed slightly less well. At similar levels of blood pressure, black patients were more likely than white patients to exhibit concentric left ventricular hypertrophy, especially among borderline hypertensive patients. Left ventricular hypertrophy occurred in patients with sustained hypertension who also exhibited increased cardiac output, strongly associated with low plasma renin activity.

Standardization of M-mode echocardiographic left ventricular anatomic measurements.

To improve standardization of echocardiographic left ventricular anatomic measurements, echographic left ventricular dimensions and mass were related to body size indexes, sex, age and blood pressure. Independent normal populations comprised 92 hospital-based subjects (64 women, 28 men) and 133 subjects from a population sample (55 women, 78 men). All measurements of chamber size, wall thickness and mass differed between men and women in both series (p less than 0.01 to p less than 0.001). Left ventricular mass was related most closely to body surface area among measurements of body size (r = 0.37, p less than 0.01 to r = 0.57, p less than 0.001) in all four groups. Indexation by body surface area eliminated sex differences in wall thicknesses and internal dimension, but a significant sex difference in left ventricular mass index persisted (89 +/- 21 g/m2 in men versus 69 + 19 g/m2 in women in the entire series, p less than 0.0001). The 97th percentile of left ventricular mass index was identical in both groups of men (136 and 132 g/m2) and women (112 and 109 g/m2). A highly significant difference in lean body mass, estimated from 24 hour urine creatine excretion, was observed between men and women (58 +/- 15 versus 40 +/- 13 kg, p less than 0.001) and no sex difference existed in left ventricular mass indexed by lean body mass (3.4 +/- 1.3 versus 3.5 +/- 1.5 g/kg). Weak correlations were observed between left ventricular mass/lean body mass and systolic or diastolic blood pressure (r = 0.25, p less than 0.05 and r = 0.28, p less than 0.01, respectively) but not age (18 to 72 years).(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic factors related to survival and complication-free times in airmen medically certified after coronary surgery.

This study was designed to identify prognostic factors for survival and complication-free times among airmen who had regained their medical certificate after coronary bypass surgery. Airmen who had petitioned the Federal Aviation Administration for a special issuance of medical certification to fly because they have had coronary bypass surgery were identified and followed retrospectively from 1970 to the end of 1980. There were 261 airmen in the study population. Demographic, medical, and prognostic information were collected on each airmen before and after surgery. Univariate and multivariate statistical methods were used in analysing the data. From the univariate analysis, presurgery diastolic blood pressure and coffee history, and postsurgery coffee history were identified as being related to complication-free time. Diagnosis for surgery, smoking history, and development of complications were identified as being related to survival after coronary bypass surgery. From the multivariate analysis, four prognostic factors: postsurgery serum cholesterol, number of grafts, postsurgery serum triglyceride, and postsurgery alcohol history were identified for complication-free time. It was concluded that using pre- and post-surgery information can help determine the long term survivors and those who will stay complication-free 11 years after coronary bypass surgery.

Contrast in cardiac anatomy and function between black and white patients with hypertension.

To determine whether cardiac findings differ between blacks and whites with essential hypertension, members of a well-defined working population in New York City were examined. Hypertensives had diastolic blood pressure ≤95, or systolic blood pressure ≤160 mmHg, or both, sustained on three occasions over three weeks. Normotensives were selected to reflect the age, sex, and race distribution of the total working population. Of 207 employees, 75 hypertensives (40 percent blacks) and 132 normotensives (53 percent blacks) under-went M-mode echocardiography. Left ventricular (LV) measurements and simultaneous blood pressure by mercury manometer were used to calculate LV mass index (LVMI), relative wall thickness (RWTd), cardiac output (CO) and total peripheral resistance (TPR). There were no differences in any variable between black and white normotensives. Black and white hypertensives were similar in age (52 ± 10 and 54 ± 12 yr, respectively) and blood pressure (151/100 ± 15/11 and 153/99 ± 18/8 mmHg). Black hypertensives had significantly higher TPR (1.80 ± 0.74 vs 1.43 ± 0.46, P<.01), lower CO (6.0 ± 2.5 vs 7.2 ± 2.4 L/min, P<.01), and higher RWTd (0.43 ± 0.11 vs 0.37 ± 0.07, P<.05) than white hypertensives. Race, per se, cannot explain these differences since they did not occur among normotensives. Rather, these findings may reflect a differing patho-physiology of hypertension in blacks and whites with similar blood pressure elevation.