Reduced pressure-volume response to exercise may reflect subclinical myocardial disease in type 2 diabetes

Abstract

Background: The predictive value of negative exercise stressechocardiography in subjects with type 2 diabetes (T2DM) isless than in those without T2DM. A reduced end-systolic pressure-volume(SP/ESV) response may identify at risk pts, but the pathophysiologyof this finding has not been determined. We sought to identifyif the abnormal SP/ESV response reflected subclinical diabeticheart disease. Methods: Myocardial dysfunction was sought with resting andexercise echo in 168 apparently healthy T2DM (97 men, 55 ±10 y). Ischemia was excluded by ExE. Conventional data, tissuevelocity, strain and strain rate were acquired at baseline andpeak stress from 6 basal segts in conventional apical views.{Delta}SP/ESV was calculated as [(peak stress systolic blood pressure/peakstress end systolic volume index) -(rest systolic blood pressure/restend systolic volume index)]. Results: Post exercise, 83 subjects showed a {Delta}SP/ESV ≤12 mmHg/ml/m2.These patients were noted to have significantly lower restingdiastolic tissue velocity, lower peak heart rates on exerciseand poorer exercise capacity than those with {Delta}SP/ESV > 12mmHg/ml/m2 [Table]. There were no significant differences betweenthe groups in terms of age, BMI, fasting glucose and systolicstrain or strain rate. In a logistic regression model incorporatingdiastolic tissue velocity, peak heart rate and exercise capacity,all were significant univariate correlates of {Delta}SP/ESV, althoughexercise capacity was the strongest (OR= 0.88, p= 0.02). Conclusions:{Delta}SP/ESV index correlates with resting diastolictissue velocity, peak heart rate and exercise capacity, allof which have known prognostic implications in T2DM. The systolicresponse to stress may provide information analogous to thatprovided by diastolic dysfunction as a marker of subclinicaldisease. © 2009 American Heart Association, Inc