Asian Indians, coronary artery disease, and physical exercise.

OBJECTIVE: To evaluate the relation of physical activity to different clinical and biochemical risk factors for coronary artery disease among people from different ethnic groups with angiographically proven coronary artery disease. SUBJECTS: British Asians, Indian Asians, and white people suffering from coronary artery disease, and their respective controls. INTERVENTIONS: History, physical examination, coronary angiography (at baseline), laboratory investigations. MAIN OUTCOME MEASURES: Relation of physical activity level to serum insulin, glucose, cholesterol, triglycerides, and high density lipoproteins, systolic and diastolic blood pressures, and body mass index in patients and controls. RESULTS: 391 male patients were studied, of whom 260 (66.5%) were classified as sedentary. Mean serum insulin at 0, 1, and 2 hours after 75 g oral glucose was higher among the sedentary population (17.1 v 11.6, 88.2 v 62.1, and 57.9 v 36.2 microU/ml, respectively (all p < 0.0001). Mean body mass index was also higher among the sedentary population (25.53 v 23.95, p < 0.0001), as were mean serum triglycerides (1.85 v 1.60 mmol/l, p < 0.01) and systolic and diastolic blood pressures (133.9 v 129.4, p < 0.05, and 81.1 v 79.0, p < 0.01). There was no difference in the mean serum cholesterol and high density lipoprotein between the two groups. British Asians were the most sedentary and Indian Asians the most physically active. CONCLUSIONS: There are marked differences in the level of physical activity among the various ethnic groups in the United Kingdom. In each ethnic group, physical activity reduced mean serum insulin, body mass index, and serum triglycerides and had a favourable effect on systolic and diastolic blood pressures. Promotion of physical activity could be of value for the Asian community in the United Kingdom.

Are Asian coronary arteries smaller than Caucasian? A study on angiographic coronary artery size estimation during life.

Asian immigrants to the UK have a higher mortality from coronary artery disease (CAD) than native Caucasians. There is a clinical impression that Asians have smaller coronary arteries than Caucasians. In the present study, consecutive series of 72 male Caucasian and 70 male Asian patients undergoing diagnostic coronary angiography were recruited. Measurements of proximal disease-free segments of the three major coronary arteries were made using the catheter tip as the calibrating object. Electronic callipers were used for all measurements. Total coronary artery diameter was derived by adding the diameters of right, left anterior descending and circumflex arteries. Asians had significantly smaller total vessel diameter compared to Caucasians. They also had smaller body surface areas. This observation has important therapeutic implications regarding coronary intervention in this ethnic group already suffering excess mortality from CAD.

Insulin resistance, high prevalence of diabetes, and cardiovascular risk in immigrant Asians. Genetic or environmental effect?

OBJECTIVES: To compare the prevalence of diabetes, hyperinsulinaemia, and associated metabolic abnormalities in immigrant Asians, Asians in India, and native white British men. DESIGN: Case control study. SETTING: Wythenshawe Hospital, Manchester, United Kingdom, and Maulana Azad Medical School, New Delhi, India. SUBJECTS: Men with angiographically proved coronary artery disease; 83 British Asians, 87 white men, and 30 Indian Asians with age matched controls. INTERVENTIONS: Fasting lipid concentrations, serum glucose, and total insulin concentrations were measured in the fasting state and one and two hours after a 75 g glucose load by mouth. All subjects had a physical examination by the same observer. RESULTS: Asians in the United Kingdom and in India had a higher prevalence of diabetes and impaired glucose tolerance than the white British men. Patients in all three ethnic groups had higher total insulin concentrations than their controls in the fasting state and after the glucose load. British Asian and Indian Asian patients and controls had higher total insulin concentrations than the white men in the fasting state and after the glucose load. Total insulin concentrations were similar in British and Indian Asians, though fasting concentrations were higher in British Asians than Indian Asians. White men had similar cholesterol, lower triglyceride, and higher high density lipoprotein cholesterol concentrations than Asians in the United Kingdom and in India. British Asian patients had higher cholesterol concentrations and British Asian controls had higher triglyceride concentrations than the Indian Asian groups. Asian patients and controls were more active. British and Indian Asian patients had higher waist to hip ratios than controls. The waist to hip ratio was positively correlated with insulin and triglyceride concentrations and negatively correlated with the high density lipoprotein cholesterol concentration. Fasting insulin and high density lipoprotein concentrations were independent predictors of coronary artery disease in white men, whereas in British Asians the waist to hip ratio was the strongest independent predictor. In Indian Asians the waist to hip ratio and high density lipoprotein concentration were independent predictors of coronary artery disease. CONCLUSIONS: Central obesity in the subgroups of Asians studied showed a close association with hyperinsulinaemia and the risk of coronary artery disease. A predisposition to insulin resistance and its metabolic abnormalities in this group of Asians seems to be genetically determined, environmental changes after migration having only a small additional effect.

Angiographic comparison of coronary artery disease between Asians and Caucasians.

Asians in the United Kingdom surpass the already high mortality from coronary artery disease seen in Caucasians. In the present study, the angiographic features of consecutive series of 87 Caucasians, 83 British Asian and 30 Asian patients in India with coronary artery disease were assessed. Blood samples at fasting and after ingestion of 75 g of dextrose were taken to assess the extent of diabetes. Fasting blood samples were also taken for measurement of cholesterol, high-density lipoprotein cholesterol and triglyceride. Coronary angiograms were scored by two independent observers who were blinded to the patients' ethnic origin. The Asians were younger than the Caucasians, but did not differ in their body mass index, systolic or diastolic blood pressure or in cigarette consumption. Lipids were similar apart from Indian Asians having lower cholesterol than British Asians, and Caucasians having lower triglyceride than Asians. There were more diabetics in Asians than in Caucasians. Asians in Britain wait longer than Caucasians and Asians in India from onset of angina to undergoing coronary angiography. The presence of triple vessel disease was not significantly different (P = 0.19) in the three groups, that is, 38%, 43% and 27% in Caucasians, British Asians and Indian Asians, respectively. The geometric mean coronary score was 26.3 (C.I. 22.6-30.6), 25.3 (C.I. 21.8-29.4), and 25.2 (C.I. 19.6-32.5) in Caucasians, British Asians and Indian Asians, respectively. This difference was not significant (P = 0.92). Total number of lesions more than three were similar, that is, in 25% Caucasian, 41% British Asian and 40% Indian Asian patients (P < 0.10). British Asians had less proximal disease (P = 0.0002), and Indian Asians less distal disease (P = 0.003) compared to Caucasians. Non-discrete (long) lesions were more prevalent in Asians than Caucasians (P = 0.0005) The total number of lesions more than three in diabetic Asians was significantly more than in the non-diabetic, 71% versus 31% in British Asians (P = 0.002) and 90% versus 15% in Indian Asians (P= 0.0001). The relationship between diabetes and long lesions in both British and Indian Asians was highly significant (P < 0.00001 and P < 0.001, respectively). Thus severity and extent of coronary disease is no different in Asians as compared to Caucasians. Diabetes is perhaps responsible for the more diffuse disease seen in Asians.

Relationship between angiographically assessed coronary artery disease, plasma insulin levels and lipids in Asians and Caucasians.

In the present study the association between angiographically demonstrated coronary artery disease lipid subfractions and insulin in Caucasians, Asian migrants to the UK and Asians in India was studied. Patients having at least one angiographic lesion of more than 50% were recruited and angiograms scored by two independent observers, blindly. There were 87 Caucasian, 83 British Asian and 30 Indian Asian patients. Lipid subfractions measured were cholesterol, HDL cholesterol, triglyceride, apo A1, apo B, Lp(a). Estimation of glucose and insulin was carried out at fasting and after two hours of oral 75 g glucose. Asians were younger than Caucasians. They did not differ in their body mass index, systolic and diastolic blood pressure or cigarette consumption. In all three ethnic groups cholesterol, LDL cholesterol and apo B showed significant positive association. Insulin levels at fasting or post glucose challenge failed to show any association. Apo B may be an additional marker for coronary artery disease in the ethnic groups studied.

Family history as an independent risk factor of coronary artery disease.

The relationship between family history of ischaemic heart disease and the presence of coronary heart disease was studied in 387 patients undergoing routine coronary arteriography prior to valve replacement. One hundred and seven patients (27.6%) had a family history of ischaemic heart disease. Of these, 52 (48.6%) had significant coronary artery disease compared with 60 of 280 (21.4%) patients without a family history (P < 0.001). The overall severity (coronary score) and extent (number of vessels) of coronary artery disease was greater in those patients with a family history (P < 0.001). Moreover, the incidence of significant coronary disease increases as the number of relatives with ischaemic heart disease also increase (P < 0.001). Multiple logistic regression analysis suggests that family history is an independent predictor of the presence of significant coronary artery disease.

A comparison of buccal nitroglycerin and sublingual nitroglycerin in the prophylaxis and treatment of exertional (situation-provoked) angina pectoris.

Suscard is a buccally administered formulation which provides rapid introduction of nitroglycerin directly into the systemic circulation and, by virtue of its sustained-release properties, may confer protection against anginal attacks for several hours. Its efficacy has been established in angina pectoris and more recently its usefulness has been extended to include the management of unstable angina and acute heart failure. Buccal nitroglycerin combines the possibilities of short-term treatment and more extended prophylaxis. In a multicentre double-blind study the efficacy of buccal nitroglycerin and sublingual nitroglycerin were compared in patients with proven chronic stable exercise-induced angina as regards anginal attacks and capacity for physical activity. The conclusion is that the two formulations of nitroglycerin have a comparable effect in the treatment of acute attacks of angina pectoris. Buccal nitroglycerin has many advantages when used prophylactically. This is documented by less frequent anginal attacks and a more prolonged duration of effect resulting in an increased physical activity.

Comparison of once and twice daily oral dosing schedules of bevantolol, a new beta-adrenoceptor antagonist with alpha-adrenoceptor partial antagonist activity in patients with angina of effort.

In a placebo controlled double-blind cross-over study following a dose titration phase, we compared the efficacy of benantolol, a new beta 1 adrenoceptor antagonist with alpha-adrenoceptor partial antagonist activity at 12 and 24 hours after dosing in patients with angina of effort. Twenty patients aged 43-65 years were studied. Each study phase lasted four weeks. Efficacy was determined by treadmill exercise testing using the standard Bruce protocol at the end of each phase. Fifteen patients satisfactorily completed the study. Data from five protocol violators were not analysed. In the four patients who received bevantolol 200 mg daily, exercise time increased from 395 +/- 192 (mean +/- 1 SD) sec on placebo to 468 +/- 171 sec at 10-12 hours and to 442 +/- 230 sec at 22-24 hours after dosing with bevantolol. In the eleven patients who received bevantolol 400 mg daily, exercise tolerance of 290 +/- 103 sec on placebo increased to 408 +/- 112 sec at 10-12 hours (P = 0.001) and to 400 +/- 98 sec at 22-24 hours (P = 0.001) after dosing with bevantolol. Maximum exercise capacity at 10-12 and 22-24 hours after dosing with bevantolol were comparable. Maximum exercise heart rate and systolic blood pressure on placebo and on bevantolol at 10-12 and at 22-24 hours after dosing were comparable. Thus, bevantolol has salutary effects on exertional angina up to 24 hours after dosing.

Surgical implications of anomalous aortic origin of the left coronary artery.

We report a patient with exertional chest pain and anomalous aortic origin of the left coronary artery from the right coronary sinus. This patient also had circumflex coronary and right coronary artery stenoses. Following coronary bypass grafting of the circumflex and right coronary arteries in this patient, angina persisted and there was abnormal septal perfusion shown on the exercise thallium imaging despite patent grafts. The angina and perfusion defect were improved by bypass grafting of the unstenosed left anterior descending coronary artery in this patient. Thallium imaging may be useful in the preoperative assessment of patients with this anomaly.

Accelerated atherosclerosis and myocardial infarction complicating anomalous origin of the right from the left coronary artery.

A patient is described in whom a previously unstenosed single coronary artery was complicated 12 months later by anterior myocardial infarction. Full clinical features documented by exercise thallium scintigraphy and coronary angiography before and after myocardial infarction are described.

Actuarial analysis of late results after closed mitral valvotomy.

The long-term results of closed mitral valvotomy performed between 1978 and 1985 in 198 patients with noncalcific mitral stenosis were analyzed. Follow-up data were available on 185 patients (93%); 1 patient died in the postoperative period, and 12 foreign patients were lost to follow-up. At the 4-year and 8-year intervals, 91% and 80% of patients, respectively, were event free (not in need of further operative procedures). By multivariate analysis, the factor preoperative mild mitral regurgitation showed a tendency to influence the event-free period. By univariate analysis, postoperative mitral regurgitation significantly reduced the event-free period. Twenty-one patients subsequently underwent mitral valve replacement; 8 for mitral regurgitation, 10 for mitral stenosis, and 3 for mixed mitral regurgitation and stenosis. By multivariate analysis, the reason for reoperation significantly influenced the length of the event-free period. The patients with mitral regurgitation required mitral valve replacement sooner than those with mitral stenosis. Advanced age, sex, previous valvotomy, preoperative New York Heart Association Functional Class, low mitral valve leaflet excursion, and pulmonary hypertension had no influence on the long-term result.

Thallium-201 myocardial imaging in patients with angina pectoris and anomalous aortic origin of the circumflex coronary artery.

Anomalous aortic origin of the circumflex coronary artery is the commonest coronary artery anomaly. In this study, the significance of anomalous aortic origin of the circumflex coronary artery was investigated in seven patients with exertional chest pain using exercise thallium scintigraphy. Five patients with circumflex coronary arterial disease served as controls. Myocardial perfusion was normal in the five patients with a nonstenosed anomalous artery. In these patients, exercise heart rate and blood pressure response were normal. Two patients with a stenosed anomalous circumflex coronary artery and four of the five control patients had posterolateral myocardial perfusion defects. It is concluded that anomalous aortic origin of the circumflex coronary artery does not cause impairment of myocardial perfusion unless it is the site of significant coronary arterial stenosis.

Left ventricular function and oesophageal function in patients with angina pectoris and normal coronary angiograms.

Left ventricular function and oesophageal function (including oesophageal manometry and pH monitoring) were investigated and a psychiatric assessment carried out in 63 patients with angina pectoris and normal coronary angiograms. Twenty two (35%) patients had regional abnormalities of left ventricular wall motion (group A). Thirty six (57%) patients had an oesophageal abnormality (group B); 19 patients had gastro-oesophageal reflux and abnormal oesophageal motility, five had gastro-oesophageal reflux alone, and 12 had abnormal oesophageal motility alone. Only four had regional abnormalities of the left ventricular wall and abnormal oesophageal function. In nine (14%) patients left ventricular and oesophageal function were normal (group C). Psychiatric morbidity was significantly less common in group A than in groups B and C and was similar in group B and group C. A definite abnormality of left ventricular function, oesophageal function, or psychiatric morbidity is present in a high proportion of patients with angina pectoris and normal coronary angiograms and in some instances this may lead to specific treatment. If quantitative assessment of left ventricular function is normal, oesophageal investigations should be performed. Endoscopy of the upper gastrointestinal tract may demonstrate oesophageal disease, but, if findings are normal, oesophageal manometry and ambulatory oesophageal pH monitoring (including during treadmill exercise testing) should be carried out.

Comparison of the performance of superflow (5F) and conventional 8F catheter for cardiac catheterization by the femoral route.

In order to determine whether the use of a smaller catheter would allow day-case cardiac catheterization by the femoral route, the performance of the Superflow (5F) and the 8F catheters was compared in 34 adults who underwent left ventriculography and coronary angiography. As shown by the significantly lower fluoroscopy time [2.8 +/- 1.2 min vs 4.5 +/- 2.7 min, (m +/- SD), p = 0.027] the 8F catheter was more maneuverable than the Superflow (5F) catheter. Poor left ventriculograms were obtained in a higher proportion of patients in whom the Superflow (5F) catheter was used. There was no significant difference in the time to achieve hemostasis at the puncture site in the two groups of patients (13 +/- 5 min vs 10 +/- 3 min, p = 0.09). It is concluded that the use of the Superflow (5F) catheter confers no advantage, while it is associated with longer screening time and poorer left ventriculograms.

Exertional gastro-oesophageal reflux: a mechanism for symptoms in patients with angina pectoris and normal coronary angiograms.

During 24 hour oesophageal pH monitoring 52 patients who had angina pectoris and normal coronary angiograms underwent exercise testing, as far as their symptoms allowed, on a treadmill to determine whether gastro-oesophageal reflux occurred during exertion. In 11 patients the 24 hour oesophageal pH score was abnormally high; 10 of these showed exertional gastro-oesophageal reflux, and in nine this was associated with their usual chest pain. A further 13 patients had a normal 24 hour pH score but had exertional reflux coincident with chest pain during exercise testing. The mean lower oesophageal sphincter pressure in both of these groups of patients was appreciably lower than that in 28 patients who had a normal 24 hour pH score and no exertional reflux. These findings suggest that exertional gastro-oesophageal reflux accounts for the symptoms of a large proportion of patients who have angina pectoris and normal coronary angiograms and that oesophageal pH monitoring during exercise testing on a treadmill enables this group of patients to be identified.

Surgical repair of acquired ventricular septal defect. Determinants of early and late outcome.

Between January 1970 and June 1985, 60 patients underwent surgical repair of postinfarction ventricular septal defect. The preoperative cineangiograms of all patients were reviewed to measure left ventricular ejection fraction and to quantitatively assess right ventricular function by measuring the percentage reduction in right ventricular midcavity diameter. There were 23 early deaths (within 30 days) and 14 late deaths occurring between 1 and 92 months after operation. Of the 23 long-term survivors, 87% are in New York Heart Association Class I or II. The early mortality was significantly higher for inferior infarction (58%) than for anterior infarction (25%). Early mortality was also influenced by the time interval between infarction and operation (under 1 week 41%, over 4 weeks 22%). Early survival was favored by good preoperative right ventricular function; the percentage reduction in right ventricular midcavity diameter was 16.5% +/- 9.5% (mean +/- standard deviation) for the early death group and 26.7% +/- 10.6% for the early survival group. However, the early outcome was not influenced by left ventricular function before operation. Conversely, long-term survival was favored by preserved preoperative left ventricular function; left ventricular ejection fraction was 26.2% +/- 9.3% for the late death group and 35% +/- 8.5% for the late survival group. Long-term survival was not, however, affected by right ventricular function before operation. The results of surgical closure of postinfarction ventricular septal defect have improved between two successive time frames in this series, which is the largest to date.