Prognostic applications of exercise testing

A basic approach to the interpretation of the exercise test

To interpret the exercise test, the following parameters need to be evaluated: the heart rate and blood pressure response, symptoms, dysrhythmias, aerobic capacity, and evidence for myocardial ischemia. When analyzing the ST segment for ischemia, the amount and type of ST depression and the time of onset and resolution are examined. The exercise test results are best used to determine a post-test probability that the patient has significant coronary disease, predict its severity, and provide a prognosis of the patient. The test allows primary care physicians to decide which patients with coronary artery disease can be safely managed medically and which high-risk patients need further evaluation and consideration for revascularization.

Infrarenal abdominal aortic aneurysm repair: detection and treatment of associated carotid and coronary lesions

Management of carotid or coronary lesions associated with abdominal aortic aneurysm (AAA) remains controversial. To determine the influence of these lesions on the outcome of elective infrarenal AAA repair, we review our experience between January 1978 and December 1992. A total of 345 consecutive patients underwent infrarenal AAA repair. Procedures were performed under emergency conditions in 62 patients (18%) and electively in 283 patients (82%). Carotid and coronary risk was assessed in all 283 patients undergoing elective operations. There were 259 men (91.5%) with a mean age of 68 years (range: 45-88 years) and 24 women (8.5%) with a mean age of 76 years (range: 59-92 years). Previous cardiac manifestations included myocardial infarction in 57 patients (20%), angina in 50 patients (17.6%), coronary bypass grafting in 14 patients (14.9%), and coronary transluminal angioplasty in two patients. Cerebral ischemic attacks had been observed in 11 patients (3.8%) including transient events in two cases. Carotid endarterectomy had been performed in two patients. Assessment of carotid artery risk using Doppler ultrasonography led to selective carotid angiography in six patients and carotid endarterectomy in two patients. Assessment of coronary risk using a cardiac stress test was performed in 204 patients. Results were normal or subnormal in 132 patients (46.6%), abnormal in 21 patients (7.4%), and uninterpretable in 51 patients (18%). Coronary arteriography was performed in 151 patients (53.3%) for secondary assessment after the cardiac stress testing in 72 patients (25%) and for primary assessment in 79 patients (27.9%). Significant coronary lesions were demonstrated in 52 patients (18% of the overall population; 34% of coronary arteriography procedures). In 12 cases the lesions were not considered as threatening. In four cases the lesions were deemed inoperable. In the remaining 36 cases the lesions were treated either by aortocoronary bypass grafting (34 cases) or percutaneous transluminal angioplasty (two cases). In 11 of the 36 treated cases the patient was asymptomatic and had no history of coronary disease. In all cases AAA was treated by resection graft. Eight patients (2.8 +/- 1%) died during hospitalization including two deaths related to preexisting cardiac insufficiency. No death was attributed to preoperative work-up or treatment of associated lesions. With a mean follow-up of 62 months (range: 1-14 years), late mortality involved 96 patients (33.9 +/- 3%) including 16 deaths due to cardiac causes (16.7 +/- 4%) and 10 due to stroke (10.4 +/- 3%). Actuarial survival including deaths during hospitalization was 70.5 +/- 3% at 5 years and 41.4 +/- 5% at 10 years. Comparison of these results with those previously reported supports our policy of performing carotid or coronary angiography in patients selected by noninvasive tests.

Prevalence of unrecognized silent myocardial ischemia and its association with atherosclerotic risk factors in noninsulin-dependent diabetes mellitus. Milan Study on Atherosclerosis and Diabetes (MiSAD) Group

To determine the prevalence of unrecognized silent myocardial ischemia, 925 noninsulin-dependent diabetic outpatients (333 women and 592 men), aged 40 to 65 years, asymptomatic, free from known coronary artery disease (CAD), advanced diabetic retinopathy, and nephropathy, severe hypertension, and poor prognosis disease, underwent exercise electrocardiogram (ECG), followed, if abnormal, by an exercise thallium scintigraphy. The exercise ECG tests were abnormal in 112 patients (12.1%, 31 women, 81 men), of whom 59 (6.4%, 12 women, 47 men) had perfusion defects at thallium scintigraphy. Adopting the more restrictive criteria (positive response to both tests) the prevalence of silent CAD resulted in 6.4%. Multivariate analysis showed that in the whole population and in the men, the associated independent risk factors were age, total cholesterol, proteinuria, and ST-T abnormalities at ECG at rest. This last factor had the highest odds ratio (9.27, confidence interval [CI] 4.44 to 19.38) and was the only one identified also in women. The relevance of ST-T abnormalities at ECG at rest as a predicting factor for silent CAD outlines the importance of a periodical ECG at rest in noninsulin-dependent diabetic patients and suggests an indication of performance of further investigations in presence of these abnormalities.