[Prognostic significance of silent ischemia in the exercise test in patients with coronary disease]. / Significado pronóstico de la isquemia silente durante la prueba de esfuerzo en pacientes con enfermedad coronaria.

To evaluate the prognostic significance of silent ischemia during exercise testing, 152 consecutive patients (143 males, 9 females) with a mean SD of 55 +/- 7 years (age range 32-73) who underwent exercise testing and coronary arteriography within 3 months were studied. All patients had the following characteristics: 1) a positive electrocardiographic exercise test response; 2) significant coronary artery disease on the arteriography; 3) uninterrupted clinical follow-up for a minimum of 6 months. The 152 patients were divided in 2 groups: group I: 56 patients (37%) with ischemic ST-segment depression during exercise testing without angina (silent ischemia); group II: 96 patients (63%) with ischemic ST-segment depression and angina (symptomatic ischemia). Patients in group I and group II showed similar time to ST-segment depression (3.6 +/- 1.5 min vs 3.2 +/- 1.4 min; p = NS), maximal ST-segment depression and peak heart rate-systolic pressure product (21,151 +/- 7,124 vs 20,456 +/- 6,024; p = NS). Exercise duration was longer in group I than in group II (5.6 +/- 2.1 min vs 4.8 +/- 1.5 min; p less than 0.001). The extent of coronary artery disease defined by the number of significant narrowed coronary vessels, left ventricular end diastolic pressure and ejection fraction were similar in the 2 groups. Sixty six patients who underwent coronary bypass surgery were not included in the analysis. The remaining 86 patients (40 in group I and 46 in group II) were medically treated. The mean follow-up period was 43,5 +/- 25 months (range 6-101).2+ myocardial ischemia during exercise testing.