What accounts for ethnic differences in newborn skinfold thickness comparing South Asians and White Caucasians? Findings from the START and FAMILY Birth Cohorts.

OBJECTIVE: South Asians are a high-risk group for type 2 diabetes and coronary heart disease. We sought to determine ethnic differences in newborn adiposity comparing South Asians (SA) to White Caucasians (Whites). METHODS: Seven hundred ninety pregnant women (401 SA, 389 Whites) and their full-term offspring from two birth cohorts in Canada were analyzed. Pregnant women completed a health assessment including a 75-g oral glucose tolerance test to assess for dysglycemia. Birthweight, length, waist and hip circumference, and triceps and subscapular skinfold thickness (a surrogate measure of body adiposity) were measured in all newborns. Multivariate regression was used to identify maternal factors associated with newborn skinfold measurements. RESULTS: South Asian women were younger (30.1 vs 31.8 years, P<0.001), their prepregnancy body mass index was lower (23.7 vs 26.2, P<0.0001) and gestational diabetes was substantially higher (21% vs 13%, P=0.005) compared with Whites. Among full-term newborns, South Asians had lower birthweight (3283 vs 3517 g, P=0.0001), had greater skinfold thickness (11.7 vs 10.6 mm; P=0.0001) and higher waist circumference (31.1 vs 29.9 cm, P=0.0001) compared with Whites. Risk factors for newborn skinfold thickness included South Asian ethnicity (standardized estimate (s.e.): 0.24; P<0.0001), maternal glucose (s.e.: 0.079; P=0.04) and maternal body fat (s.e.: 0.14; P=0.0002). CONCLUSIONS: South Asian newborns are lower birthweight and have greater skinfold thickness, compared with White newborns, and this is influenced by maternal body fat and glucose. Interventions aimed at reducing body fat prior to pregnancy and gestational diabetes during pregnancy in South Asians may favorably alter newborn body composition and require evaluation.

Parental and child genetic contributions to obesity traits in early life based on 83 loci validated in adults: the FAMILY study.

BACKGROUND: The genetic influence on child obesity has not been fully elucidated. OBJECTIVE: This study investigated the parental and child contributions of 83 adult body mass index (BMI)-associated single-nucleotide polymorphisms (SNPs) to obesity-related traits in children from birth to 5 years old. METHODS: A total of 1402 individuals were genotyped for 83 SNPs. An unweighted genetic risk score (GRS) was generated by the sum of BMI-increasing alleles. Repeated weight and length/height were measured at birth, 1, 2, 3 and 5 years of age, and age-specific and sex-specific weight and BMI Z-scores were computed. RESULTS: The GRS was significantly associated with birthweight Z-score (P = 0.03). It was also associated with weight/BMI Z-score gain between birth and 5 years old (P = 0.02 and 6.77 × 10-3 , respectively). In longitudinal analyses, the GRS was associated with weight and BMI Z-score from birth to 5 years (P = 5.91 × 10-3 and 5.08 × 10-3 , respectively). The maternal effects of rs3736485 in DMXL2 on weight and BMI variation from birth to 5 years were significantly greater compared with the paternal effects by Z test (P = 1.53 × 10-6 and 3.75 × 10-5 , respectively). CONCLUSIONS: SNPs contributing to adult BMI exert their effect at birth and in early childhood. Parent-of-origin effects may occur in a limited subset of obesity predisposing SNPs.

Prenatal and early-life predictors of atopy and allergic disease in Canadian children: results of the Family Atherosclerosis Monitoring In earLY life (FAMILY) Study.

Prenatal and early-life environmental exposures play a key role in the development of atopy and allergic disease. The Family Atherosclerosis Monitoring In earLY life Study is a general, population-based Canadian birth cohort that prospectively evaluated prenatal and early-life traits and their association with atopy and/or allergic disease. The study population included 901 babies, 857 mothers and 530 fathers. Prenatal and postnatal risk factors were evaluated through questionnaires collected during the antenatal period and at 1 year. The end points of atopy and allergic diseases in infants were evaluated through questionnaires and skin prick testing. Key outcomes included atopy (24.5%), food allergy (17.5%), cow's milk allergy (4.8%), wheezing (18.6%) and eczema (16%). The association between infant antibiotic exposure [odds ratio (OR): 2.04, 95% confidence interval (CI): 1.45-2.88] and increased atopy was noted in the multivariate analysis, whereas prenatal maternal exposure to dogs (OR: 0.60, 95% CI: 0.42-0.84) and acetaminophen (OR: 0.68, 95% CI: 0.51-0.92) was associated with decreased atopy. This population-based birth cohort in Canada demonstrated high rates of atopy, food allergy, wheezing and eczema. Several previously reported and some novel prenatal and postnatal exposures were associated with atopy and allergic diseases at 1 year of age.

Long-term effects of cholesterol lowering and angiotensin-converting enzyme inhibition on coronary atherosclerosis: The Simvastatin/Enalapril Coronary Atherosclerosis Trial (SCAT).

BACKGROUND: This long-term, multicenter, randomized, double-blind, placebo-controlled, 2 x 2 factorial, angiographic trial evaluated the effects of cholesterol lowering and angiotensin-converting enzyme inhibition on coronary atherosclerosis in normocholesterolemic patients. METHODS AND RESULTS: There were a total of 460 patients: 230 received simvastatin and 230, a simvastatin placebo, and 229 received enalapril and 231, an enalapril placebo (some subjects received both drugs and some received a double placebo). Mean baseline measurements were as follows: cholesterol level, 5.20 mmol/L; triglyceride level, 1.82 mmol/L; HDL, 0.99 mmol/L; and LDL, 3.36 mmol/L. Average follow-up was 47.8 months. Changes in quantitative coronary angiographic measures between simvastatin and placebo, respectively, were as follows: mean diameters, -0.07 versus -0.14 mm (P:=0.004); minimum diameters, -0.09 versus -0.16 mm (P:=0. 0001); and percent diameter stenosis, 1.67% versus 3.83% (P:=0.0003). These benefits were not observed in patients on enalapril when compared with placebo. No additional benefits were seen in the group receiving both drugs. Simvastatin patients had less need for percutaneous transluminal coronary angioplasty (8 versus 21 events; P:=0.020), and fewer enalapril patients experienced the combined end point of death/myocardial infarction/stroke (16 versus 30; P:=0.043) than their respective placebo patients. CONCLUSIONS: This trial extends the observation of the beneficial angiographic effects of lipid-lowering therapy to normocholesterolemic patients. The implications of the neutral angiographic effects of angiotensin-converting enzyme inhibition are uncertain, but they deserve further investigation in light of the positive clinical benefits suggested here and seen elsewhere.

Primary stenting versus balloon angioplasty in occluded coronary arteries: the Total Occlusion Study of Canada (TOSCA).

BACKGROUND: Balloon angioplasty (PTCA) of occluded coronary arteries is limited by high rates of restenosis and reocclusion. Although stenting improves results in anatomically simple occlusions, its effect on patency and clinical outcome in a broadly selected population with occluded coronary arteries is unknown. METHODS AND RESULTS: Eighteen centers randomized 410 patients with nonacute native coronary occlusions to PTCA or primary stenting with the heparin-coated Palmaz-Schatz stent. The primary end point, failure of sustained patency, was determined at 6-month angiography. Repeat target-vessel revascularization, adverse cardiovascular events, and angiographic restenosis (>50% diameter stenosis) constituted secondary end points. Sixty percent of patients had occlusions of >6 weeks' duration, baseline flow was TIMI grade 0 in 64%, and median treated segment length was 30.5 mm. With 95.6% angiographic follow-up, primary stenting resulted in a 44% reduction in failed patency (10.9% versus 19.5%, P=0.024) and a 45% reduction in clinically driven target-vessel revascularization at 6 months (15.4% versus 8.4%, P=0.03). The incidence of adverse cardiovascular events was similar for both strategies (PTCA, 23.6%; stent, 23.3%; P=NS). Stenting resulted in a larger mean 6-month minimum lumen dimension (1.48 versus 1.23 mm, P<0.01) and a reduced binary restenosis rate (55% versus 70%, P<0.01). CONCLUSIONS: Primary stenting of broadly selected nonacute coronary occlusions is superior to PTCA alone, improving late patency and reducing restenosis and target-vessel revascularization.

Effects of exercise training in patients with congestive heart failure: a critical review.

Congestive heart failure is a potentially debilitating disorder that affects a significant number of patients. The age-adjusted death rate has doubled over the past decade. Patients live an average of 4 to 5 years, and nearly all suffer from fatigue and breathlessness, which limits exercise capacity and produces a poor quality of life. Patients have usually been advised to avoid exercise because of concerns that they would experience a further decline in cardiac function. However, it has been demonstrated that exercise capacity is not related to the degree of left ventricular systolic dysfunction. This has led to the suggestion that peripheral changes in skeletal muscle and blood supply may play a major role in determining the exercise capacity of patients with congestive heart failure. Studies have demonstrated abnormalities of skeletal muscle blood flow, metabolism and structure, all of which are consistent with the impaired performance observed in these patients. Although the effects of exercise training have been examined in only a relatively few number of patients, the results have been promising. Exercise training has been found to improve exercise capacity and reduce symptoms. However, to our knowledge no data exist as to the impact of exercise training on left ventricular function, hospital stay or mortality in this population. Even though the early results are promising, they require confirmation of feasibility, clinical benefit and safety in larger, long-term randomized trials. It should be determined whether training has a long-term beneficial impact on measures more closely related to daily activities and quality of life. Ultimately, it would be important to determine whether training has an impact on mortality and morbidity.

Why do patients with atrial fibrillation not receive warfarin?

Atrial fibrillation (AF) is a growing public health problem associated with significant morbidity and mortality. Numerous randomized controlled trials of warfarin have conclusively demonstrated that long-term anticoagulation therapy can reduce the risk for stroke by approximately 68% per year in patients with nonvalvular AF, and even more in patients with valvular AF. However, available data show that of those patients with AF and no contraindication to warfarin therapy, only 15% to 44% are prescribed warfarin. Our literature review has identified patient-, physician-, and health care system-related barriers to warfarin prescription. However, the relative importance of these specific barriers remains unknown. Further work is needed to understand the discrepancy between the randomized controlled trial evidence and clinical practice patterns.

Acute precipitants of congestive heart failure exacerbations.

BACKGROUND: Few studies have prospectively and systematically explored the factors that acutely precipitate exacerbation of congestive heart failure (CHF) in patients with left ventricular dysfunction. Knowledge of such factors is important in designing measures to prevent deterioration of clinical status. The objective of this study was to prospectively describe the precipitants associated with exacerbation of CHF status in patients enrolled in the Randomized Evaluation of Strategies for Left Ventricular Dysfunction Pilot Study. METHODS: We conducted a 2-stage, multicenter, randomized trial in 768 patients with CHF who had an ejection fraction of less than 40%. Patients were randomly assigned to receive enalapril maleate, candesartan cilexetil, or both for 17 weeks, followed by randomization to receive metoprolol succinate or placebo for 26 weeks. Investigators systematically documented information on clinical presentation, management, and factors associated with the exacerbation for any episode of acute CHF during follow-up. RESULTS: A total of 323 episodes of worsening of CHF occurred in 180 patients during 43 weeks of follow-up; 143 patients required hospitalization, and 5 died. Factors implicated in worsening of CHF status included noncompliance with salt restriction (22%); other noncardiac causes (20%), notably pulmonary infectious processes; study medications (15%); use of antiarrhythmic agents in the past 48 hours (15%); arrhythmias (13%); calcium channel blockers (13%); and inappropriate reductions in CHF therapy (10%). CONCLUSIONS: A variety of factors, many of which are avoidable, are associated with exacerbation of CHF. Attention to these factors and patient education are important in the prevention of CHF deterioration.

Response to upright exercise after myocardial infarction.

The left ventricular response to upright bicycle exercise was studied in 39 unselected, non-beta blocked patients (mean(SEM) age 54.2(1.7)yr) (mean(SEM) resting ejection fraction 41.9(2.3)%) 8-10 weeks after myocardial infarction. Nine healthy, age matched, sedentary adult men were studied for comparison (mean(SEM) age 49.8(0.9)yr). The stroke volume and cardiac output were measured by impedance cardiography at rest and after each 3 min workload until symptom limited maximum. The patients were separated into three groups based on stroke volume response to graded exercise. Group 1 (n = 14) had a normal stroke volume response to increasing heart rate. In group 2 (n = 13) stroke volume increased initially then decreased by greater than 15% at a heart rate greater than 100-105 beats.min-1. In group 3 (n = 12) stroke volume failed to increase during exercise. In group 1 cardiac output and mean arterial pressure increased whereas vascular resistance decreased during exercise in a normal fashion. Group 2 had an increased mean arterial pressure and systemic vascular resistance throughout exercise while heart rate increased in a similar fashion to group 1 until work of greater than 70 W was undertaken, at which time heart rate increased in a curvilinear fashion and cardiac output was attenuated. Group 3 had an attenuated cardiac output and a higher heart rate during exercise. In this group of patients systemic vascular resistance failed to decrease normally during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac output measured by impedance cardiography during maximal exercise tests.

The overall accuracy of cardiac output measurements made by impedance cardiography during maximum exercise was studied in man. Initially, the systematic error of the technique was assessed over the range 3.5 to 18 litre . min-1 by comparing with simultaneous measurements of cardiac output made using the direct Fick method. No systemic error was demonstrated in 40 estimations made in 20 subjects. The random error was assessed in 4 subjects in a steady state at rest and during exercise at 80 and 130 W and found to be less than 5% in each subject. The reproducibility of maximum exercise response was assessed in six healthy male subjects (age 26.2 +/- 4.4 years, +/- SEM) who underwent maximum exercise tests twice, 1 week apart, on a bicycle ergometer. Simultaneous recordings of cardiac output and oxygen uptake (VO2) at rest and during each 3 min stage of exercise were made. Highly significant correlations were obtained in the stroke volume (r = 0.84, p less than 0.001), cardiac output (r = 0.98, p less than 0.001) and VO2 (r = 0.98, p less than 0.001) between the two tests. Average maximum cardiac output was 27.0 +/- 1.2 litre . min-1 (+/- SEM) and maximum VO2 was 4.4 +/- 0.2 litre . min-1 (+/- SEM). These results show that measurements of cardiac output were reproducible over one week. Impedance cardiography is non-invasive technique which is as accurate as invasive methods and can be used for maximal exercise testing.

Variations in common diseases, hospital admissions, and deaths in middle-aged adults in 21 countries from five continents (PURE): a prospective cohort study

BACKGROUND: To our knowledge, no previous study has prospectively documented the incidence of common diseases and related mortality in high-income countries (HICs), middle-income countries (MICs), and low-income countries (LICs) with standardised approaches. Such information is key to developing global and context-specific health strategies. In our analysis of the Prospective Urban Rural Epidemiology (PURE) study, we aimed to evaluate differences in the incidence of common diseases, related hospital admissions, and related mortality in a large contemporary cohort of adults from 21 HICs, MICs, and LICs across five continents by use of standardised approaches. METHODS: The PURE study is a prospective, population-based cohort study of individuals aged 35-70 years who have been enrolled from 21 countries across five continents. The key outcomes were the incidence of fatal and non-fatal cardiovascular diseases, cancers, injuries, respiratory diseases, and hospital admissions, and we calculated the age-standardised and sex-standardised incidence of these events per 1000 person-years. FINDINGS: This analysis assesses the incidence of events in 162 534 participants who were enrolled in the first two phases of the PURE core study, between Jan 6, 2005, and Dec 4, 2016, and who were assessed for a median of 9·5 years (IQR 8·5-10·9). During follow-up, 11 307 (7·0%) participants died, 9329 (5·7%) participants had cardiovascular disease, 5151 (3·2%) participants had a cancer, 4386 (2·7%) participants had injuries requiring hospital admission, 2911 (1·8%) participants had pneumonia, and 1830 (1·1%) participants had chronic obstructive pulmonary disease (COPD). Cardiovascular disease occurred more often in LICs (7·1 cases per 1000 person-years) and in MICs (6·8 cases per 1000 person-years) than in HICs (4·3 cases per 1000 person-years). However, incident cancers, injuries, COPD, and pneumonia were most common in HICs and least common in LICs. Overall mortality rates in LICs (13·3 deaths per 1000 person-years) were double those in MICs (6·9 deaths per 1000 person-years) and four times higher than in HICs (3·4 deaths per 1000 person-years). This pattern of the highest mortality in LICs and the lowest in HICs was observed for all causes of death except cancer, where mortality was similar across country income levels. Cardiovascular disease was the most common cause of deaths overall (40%) but accounted for only 23% of deaths in HICs (vs 41% in MICs and 43% in LICs), despite more cardiovascular disease risk factors (as judged by INTERHEART risk scores) in HICs and the fewest such risk factors in LICs. The ratio of deaths from cardiovascular disease to those from cancer was 0·4 in HICs, 1·3 in MICs, and 3·0 in LICs, and four upper-MICs (Argentina, Chile, Turkey, and Poland) showed ratios similar to the HICs. Rates of first hospital admission and cardiovascular disease medication use were lowest in LICs and highest in HICs. INTERPRETATION: Among adults aged 35-70 years, cardiovascular disease is the major cause of mortality globally. However, in HICs and some upper-MICs, deaths from cancer are now more common than those from cardiovascular disease, indicating a transition in the predominant causes of deaths in middle-age. As cardiovascular disease decreases in many countries, mortality from cancer will probably become the leading cause of death. The high mortality in poorer countries is not related to risk factors, but it might be related to poorer access to health care. (AU)

Perhexiline during exercise training in coronary heart disease.

The effects of low-dose perhexiline on the exercise training response of 22 male patients, 14 after myocardial infarction and 8 after coronary artery bypass who underwent exercise training, were examined. All subjects underwent treadmill exercise testing and resting left ventricular function evaluation by radionuclide ventriculography before and after an 8-wk course of three-times-weekly exercise training. Blood levels of perhexiline confirmed that there was a steady state sufficient for antianginal therapy. There were no side effects. There were improvements in exercise tolerance in treated and placebo groups. There were no significant intergroup differences. Resting left ventricular ejection fraction and end-systolic and diastolic dimensions were not altered. Resting blood pressures were not affected by treatment. There was no evidence of a beta-adrenoceptor-blocking effect. Perhexiline during exercise training did not impair the training response.

A systematic review of randomized trials of disease management programs in heart failure.

PURPOSE: Disease management programs are often advocated for the care of patients with chronic disease. This systematic review was conducted to determine whether these programs improve outcomes for patients with heart failure. METHODS: Randomized clinical trials of disease management programs in patients with heart failure were identified by searching Medline 1966 to 1999, Embase 1980 to 1998, Cinahl 1982 to 1999, Sigle 1980 to 1998, the Cochrane Controlled Trial Registry, the Cochrane Effective Practice and Organization of Care Study Registry, and the bibliographies of published studies. We also contacted experts in the field. Studies were selected and data extracted independently by two investigators, and summary risk ratios (RR) and 95% confidence intervals (CI) were calculated using both the random and fixed effects models. RESULTS: A total of 11 trials (involving 2,067 patients with heart failure) were identified. Disease management programs were cost saving in 7 of the 8 trials that reported cost data and also appeared to have beneficial effects on prescribing practices. Hospitalizations (RR = 0.87, 95% CI: 0.79 to 0.96) but not all-cause mortality (RR = 0.94, 95% CI: 0.75 to 1.19) were reduced by the programs. However, there were considerable differences in the effects of various interventions on hospitalization rates; specialized follow-up by a multidisciplinary team led to a substantial reduction in the risk of hospitalization (RR = 0.77, 95% CI 0.68 to 0.86, n = 1366), whereas trials employing telephone contact with improved coordination of primary care services failed to find any benefit (RR = 1.15, 95% CI 0.96 to 1.37, n = 646). CONCLUSION: Disease management programs for the care of patients with heart failure that involve specialized follow-up by a multidisciplinary team reduce hospitalizations and appear to be cost saving. Data on mortality are inconclusive. Further studies are needed to establish the incremental benefits of the different elements of these programs.

Critical review of the approaches to the prevention of sudden death.

The types of cardiac rhythm in patients with sudden death may vary considerably, depending on the underlying cardiac disease. Although ventricular tachyarrhythmias are likely to be the most common causes, a significant proportion of patients may die suddenly due to asystole, electromechanical dissociation, or cardiac rupture. Therefore, the approaches to preventing sudden death may have to be multifactorial. The classic approach of arrhythmia suppression by empiric antiarrhythmic drugs has not resulted in a decrease in sudden death mortality. Although beta blockers have only a modest effect in suppressing arrhythmias, they have been clearly proven to prevent sudden death. Other promising approaches that require further evaluation include modulation of the autonomic balance between the sympathetic and parasympathetic nervous systems (perhaps by beta blockers, exercise training, or low-dose atropine or scopolamine), relief of ischemia by medical or surgical therapy, magnesium supplementation, and mechanical devices, such as the implantable defibrillator.

Evolution of the responses to exercise in left ventricular aneurysms after anterior wall acute myocardial infarction.

The evolution of the heart rate, blood pressure and electrocardiographic responses to exercise in 20 patients (group A) who exhibited echocardiographic evidence of left ventricular (LV) aneurysms after acute myocardial infarction (AMI) were examined. The responses were compared with those seen in 19 patients without LV aneurysms who were matched for age, gender and location of infarct (group B). Patients taking beta blockers were excluded from the study. It was found that the heart rate response to exercise was accentuated in group A at the time of discharge from hospital and that it became attenuated over 9 to 12 months. The blood pressure response was significantly increased over 9 to 12 months in group B. Persistence of ST elevation during exercise, 10 to 12 weeks after AMI, was diagnostic of an LV aneurysm. One year after AMI the sensitivity of ST elevation was 90%, specificity was 95% and the negative predictive value 90%.

Importance of considering ventricular function when prescribing exercise after acute myocardial infarction.

This investigation was undertaken in patients who had an acute myocardial infarction 12.6 +/- 0.4 months earlier to determine, using conventional methods, the nature of stroke volume changes during training regimens. Twenty-seven patients (mean age 52 +/- 2 years; rest ejection fraction 49 +/- 2%; New York Heart Association functional class I or II) and 9 normal, age-matched sedentary control subjects (mean age 50 +/- 1 years) exercised in the upright position on a bicycle ergometer. Stroke volume was measured by impedance cardiography at rest and after each workload. Ten patients (group A) had a stroke volume response similar to that of the normal sedentary subjects. In 8 patients (group B) the stroke volume increased initially, then decreased (more than 15%) at heart rates (HRs) greater than 100 to 105 beats/min. Nine patients (group C) had a flattened stroke volume response throughout exercise. Training HR determined by conventional methods corresponded to a maximal stroke volume in the normal subjects. Training HR in group A corresponded to a stroke volume that was maximal or near-maximal. Training HR in group B corresponded to a maximal or diminishing stroke volume. In group C, the training HR corresponded to a stroke volume no different from that at rest. Thus, training HR determined by conventional methods based solely on the chronotropic responses to exercise may place patients who have abnormal stroke volume responses to upright exercise in a situation during training sessions in which an inappropriately high HR, excessive fatigue or silent ischemia may develop.

Influence of beta blockade on exercise capacity and heart rate response after human orthotopic and heterotopic cardiac transplantation.

It has been reported that use of beta blockers may not be safe after cardiac transplantation because the denervated hearts may be largely dependent on circulating catecholamines to increase cardiac output. Therefore, the effects of intravenous propranolol were studied during maximal treadmill exercise in 7 patients with heterotopic and 6 with orthotopic cardiac transplantations. An average decrease of about 15% in exercise duration (p less than 0.001), a 34% reduction in systolic blood pressure increase (p less than 0.05) and a 40% attenuation in heart rate increase (p less than 0.001) were observed after beta blockade. In patients with heterotopic transplantation, beta blockade produced similar effects on heart rate in the denervated donor hearts and the innervated recipient hearts during and after mild exercise. During peak exercise, beta blockade attenuated the rate to a greater extent in the donor hearts. Although the denervated donor heart is more sensitive to beta blockade than the innervated recipient heart during exercise, no adverse effects were observed. Beta-blocker therapy should be considered for cardiac transplant patients if longer-term studies confirm their safe use in these patients.

Cardiovascular responses to early exercise in inferior wall ST acute myocardial infarction.

The heart rate and blood pressure responses to standardized exercise tests were studied in a group of patients with electrocardiographic evidence of inferior wall acute myocardial infarction (AMI). The tests were done on a bicycle ergometer at 8 to 10 days and 10 to 12 weeks after AMI. At 8 to 10 days after AMI, those with ST AMI (n = 12) had a significantly reduced heart rate response to exercise compared with patients with Q-wave AMI (n = 25). This difference was not evident at 10 to 12 weeks. The systolic blood pressure response in patients with ST AMI was lower than that of Q-wave AMI patients during the first exercise test, although the difference did not attain statistical significance but was significantly lower than the responses of both groups at the second test. The patients with ST AMI had smaller amounts of myocardial damage than those with Q-wave AMI as indicated by plasma creatine kinase values (p less than 0.01). These differences in the heart rate responses appeared to result from the preferential activation of nonmyelinated afferent fibers in the subepicardial region of the inferior wall of the myocardium.

Effects of late percutaneous transluminal coronary angioplasty of an occluded infarct-related coronary artery on left ventricular function in patients with a recent (< 6 weeks) Q-wave acute myocardial infarction (Total Occlusion Post-Myocardial Infarction Intervention Study [TOMIIS]--a pilot study).

The effect of late percutaneous transluminal coronary angioplasty (PTCA) of an occluded infarct-related artery on left ventricular ejection fraction was studied in patients with a recent, first Q-wave myocardial infarction in a prospective, randomized study. Forty-four patients (31 men and 13 women, mean age 58 +/- 12 years) with an occluded infarct-related coronary artery were randomized to PTCA (n = 25) or no PTCA (n = 19). Patients received acetylsalicylic acid, a beta blocker and an angiotensin-converting enzyme inhibitor unless contraindicated. Left ventricular ejection fraction was determined at baseline and 4 months. Coronary angiography was repeated at 4 months. Baseline ejection fraction measured 20 +/- 12 days after myocardial infarction was 45 +/- 12% in both groups. PTCA was performed 21 +/- 13 days after the event. The primary PTCA success rate was 72%. One patient in each group died before angiographic follow-up, which was completed in 37 of the remaining 42 patients (88%; 21 with and 16 without PTCA). At 4 months, the infarct-related artery was patent in 43% of PTCA patients and in 19% of no PTCA patients (p = NS). Reocclusion occurred in 40% of patients after successful PTCA. Secondary analyses showed that the change in left ventricular ejection fraction was significantly greater in patients with a patent infarct-related artery (+9.4 +/- 6.2%) than in those with an occluded artery (+1.6 +/- 8.8%; p = 0.0096). Baseline ejection fraction also independently predicted improvement in left ventricular ejection fraction (p = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of risk and patterns of practice in patients older and younger than 70 years with acute myocardial infarction in a two-year period (1987-1989)

To further evaluate contemporary risk and practice patterns in acute myocardial infarction (AMI), 402 consecutive patients with AMI between July 1, 1988, and June 30, 1989 were studied. The clinical investigations, medical therapy and outcome of patients aged greater than or equal to 70 years (n = 132; group 1) were compared with patients aged less than 70 years (n = 270; group 2). In group 1, 20% of patients had no typical cardiac pain versus 6% in group 2 (p less than 0.01). History of previous AMI, Q-wave AMI and peak creatine kinase were not different in the 2 groups. In-hospital mortality was markedly higher in group 1 (27%) than in group 2 (8%), p less than 0.01. Multivariate analysis revealed previous AMI, presentation without typical pain and age greater than or equal to 70 years to be independently associated with the greatest relative risk. Post-AMI exercise testing, ejection fraction calculations and coronary angiography were all performed less often (p less than 0.01); proven effective medical therapies, including thrombolysis, beta blockers, acetylsalicylic acid and nitrates were all used less frequently (p less than 0.01). The very high mortality and less aggressive management of elderly patients with AMI confirm similar data from our 1987 AMI patient cohort and other recently reported AMI patient outcome analyses. However, it remains uncertain why older patients with AMI are investigated and treated differently from younger patients. Further studies are warranted.