Search

OBJECTIVES--To study the risk factors for cardiac mortality after coronary artery bypass graft surgery. DESIGN AND SETTING--Follow up study of patients who had undergone coronary artery bypass graft surgery at the University Hospital of Oulu, Finland. PATIENTS AND INTERVENTIONS--339 consecutive patients who underwent cardiac catheterisation three months after bypass surgery. MAIN OUTCOME MEASURES--Incidence of cardiac deaths during the follow up period of five years and predictive value of clinical and angiographic variables for subsequent cardiac mortality. RESULTS--The incidence of cardiac deaths was 5.1%, and 81% of these were sudden deaths. The postoperative ejection fraction was significantly lower in the patients with subsequent cardiac death than in the survivors (p less than 0.001), and their left ventricular end systolic and end diastolic volumes were higher (p less than 0.001 and p less than 0.05 respectively). The incidence of cardiac deaths was 43% in the patients with a postoperative ejection fraction of less than 40%. The myocardial jeopardy index after surgery and the rate of graft patency were not significantly different in the survivors and patients who died. The only clinical factors that were different between the groups were postoperative use of diuretics (p less than 0.001) or digitalis (p = 0.02). After adjustment for other prognostic variables by the proportional hazards method, a low postoperative ejection fraction remained significant as a predictor of the relative risk of cardiac mortality five years after operation (p less than 0.01). CONCLUSIONS--Patients with angiographic evidence of impaired left ventricular function after bypass surgery are still at relatively high risk of dying suddenly, but myocardial ischaemia due to incomplete revascularisation is not strongly associated with an increased risk of cardiac mortality. Conventional clinical methods do not seem to be helpful for identifying patients with an increased risk of cardiac death after bypass surgery. [ABSTRACT FROM PUBLISHER]

Thallium tomographic imaging and exercise electrocardiography were performed on 136 diabetic patients without symptoms of heart disease. Thirty three patients had post-exercise thallium defects and 19 had ST 1 mm greater than or equal to segment depression during exercise electrocardiography. Both tests were positive in 13 patients. Coronary angiography was subsequently performed on 33 patients with either scintigraphic and/or electrocardiographic evidence of myocardial ischaemia. Angiographically significant coronary artery disease (greater than or equal to 50% narrowing of the coronary artery lumen) was detected in 13 patients. Six patients had minimal coronary artery stenosis (less than 50%), and 14 had normal coronary arteries. Six patients refused cardiac catheterisation. In 14 out of 27 patients with post-exercise thallium defects coronary angiography did not show any coronary artery stenoses (positive predictive accuracy 48%). Exercise electrocardiography showed only one false positive result (positive predictive accuracy 94%) but failed to detect coronary artery disease in three patients with a positive scintigraphic result. The accuracy of a positive exercise electrocardiographic test seems to be better than that of a positive thallium tomographic scan for detecting asymptomatic coronary artery disease in diabetic patients. The high number of false positive thallium defects may be the result of technical features inherent in thallium tomography and/or the possible disease of the small intramyocardial arteries in diabetic patients. [ABSTRACT FROM PUBLISHER]

Heart rate variation in deep breathing, a sensitive non-invasive measure of cardiac parasympathetic activity, was measured in 63 patients with coronary artery disease, in 22 patients with atypical chest pain, and in 20 healthy symptom free volunteers. There was significantly less heart rate variation in deep breathing in the patients with coronary artery disease than in the healthy subjects. Twenty patients (32%) with coronary artery disease had lower than normal variation in heart rate. The patients with chest pain showed an intermediate heart rate response to deep breathing. Sinus arrhythmia in the patients with coronary artery disease was not related to the functional class, medication, number or location of narrowed vessels, or to the left ventricular ejection fraction, and end diastolic pressure. These results suggest that impairment of the parasympathetic nervous function is common in coronary artery disease. [ABSTRACT FROM PUBLISHER]