190 Arrhythmic disorders and physiologic response during dobutamine stress echocardiography after acute myocardial infarction - influence of diabetes on

Abstract

1 1 Medical University, II Chair of Cardiology, Lodz, Poland Aim: The purpose of the study was to evaluate long-term prognostic value of pharmacological stress echocardiography (SE) in patients with and with- out hypercholesterolemia (HCH). Methods: We followed 224 patients (62% men, age 55±10 yrs) who had undergone SE as the diagnostic test for ischemic heart disease. Myocardial infarction, need for revascularization or death were defined as endpoints (MACE) during the follow-up period of 53 months (range 12 to 91). The prog- nostic value of the test in patients with (50%) and without HCH was compared. Results: The prevalence of risk factors were: 44% for hypertension, 50% - hypercholesterolemia, 62% - history of smoking, 31% - previous myocardial infarction, 12% - diabetes. SE was positive for ischemia in 108 patients (48%). During then follow-up period 21 patients died (9%) and 102 (45%) experi- enced MACE. HCH and positive SE were independent predictors of events (Cochran-Cox: p=0.001, p<0.0001 respectively). However, positive result of SE in patients without HCH had higher prognostic value for MACE as com- pared with subset with HCH (HR: 3.57, p=0.0001 and HR: 2.05, p=0.003 respectively). Conclusion: In unselected patients undergoing diagnostic SE the presence of hypercholesterolemia limits the predictive value of positive SE for MACE. Patients and methods: The investigation comprised 128 patients, 55 diabet- ics (D) and 73 non-diabetics (ND) all with non-complicated AMI. 90 patients (70.3%) received thrombolityc therapy. After 10-12 days all of them underwent DSE testing and during the next 3-6 months coronary angiography. Results: Non-sustained ventricular and supraventricular tachycardia occurred in 7 D (12.7%) and 9 ND (12.3%) and in 6 D (10.9%) and 12 ND (16.4%). In 5 ND (6.8%) junction rhythm was developed, and in 4 D (7.2%) and 3 ND (4.1%) AV block II-III. Systolic blood pressure decrease of ≥ 40 mm Hg oc- curred in 6 D (10.9%) and 10 ND (13.7%). Significant coronary stenoses were found in 45 (81.8%) D and 42 (57.5%) ND. Diabetics vs non-diabetics had a higher baseline heart rate (83±11 vs 69±11 beats/min, p<0.001), with a higher age-predicted maximum heart rate at peak. In non-diabetics group there was no significant difference between patients with and without arrhythmias, regarding the mean number of diseased coronary arteries (1.61±0.7 vs 1.58±0.6). In diabetic group, patients with arrhythmias had greatest number of diseased coronary arteries (2.7±0.7 vs 1.52±0.4) Inde- pendent predictors of arrhythmias were: higher resting WMSI (p<0.01), and diabetes (p<0.1). Independent predictors of systolic blood pressure decrease of l 40 mm Hg were: higher baseline systolic pressure (p<0.0001); hyper- trophic left ventricle with diastolic dysfunction; and higher resting WMSI with systolic dysfunction. Conclusion: Physiological responses to dobutamine stress are comparable in diabetics and non-diabetics, except that a more rapid heart rate response is found in diabetics. Arrhythmic disorders during DSE in diabetic patients are predicted not only by the extent of systolic or diastolic left ventricular dysfunction, but also by the presence or the extent of CAD.