Exercise induced increase in diastolic blood pressure. Is it an indicator of coronary artery disease?

It has been previously reported that an increase in diastolic blood pressure greater than 15 mmHg comparing values at rest with those on treadmill exercise, with or without ST changes, enhances the probability of coronary artery disease. To investigate whether the diastolic blood pressure variation keeps its diagnostic value during upright bicycle exercise, we evaluated the diastolic blood pressure variations in 111 patients with angiographically documented coronary artery disease without previous myocardial infarction and in 53 patients with normal coronary arteries undergoing maximal stress testing on a bicycle ergometer. The sensitivity of diastolic blood pressure (DBP) variations to detect coronary artery disease was 66%, the specificity 32%, the positive predictive value 67%, the negative predictive value 31% and the predictive accuracy 55%. The respective values for ST depression were 83% (P less than 0.001 vs DBP variations), 53% (P less than 0.05 vs DBP variations), 64% (P less than 0.05 vs DBP variations) and 75% (P less than 0.001 vs DBP variations). Forty-nine of the 75 patients with multivessel coronary artery disease and 60 of the 89 patients without coronary artery disease or with single vessel disease had abnormal DBP variations (sensitivity 65; specificity 33%). The sensitivity of ST segment depression in predicting multivessel disease was 91% (P less than 0.001 vs DBP variations), and the specificity 42%. Thus, for bicycle ergometer exercise testing, ST segment depression seems to be more accurate than DBP variations in the diagnosis of coronary artery disease.