Abstract 3648: Hypotensive Response During Exercise Myocardial Perfusion Imaging: Does It Have Independent Long Term Prognostic Value?
Background: Hypotensive response (HypoR) during exercise is a known high risk marker for significant LV dysfunction predicting higher probability of critical and/or multivessel disease. Long term prognostic implications of HypoR in the setting of exercise myocardial perfusion imaging (EMPI) has not been studied as most of these patients undergo diagnostic angiography and revascularization given the immediate implications of HypoR.
Methods: Retrospective study of consecutive patients EMPI between 1997 and 2002 followed by coronary angiogram (CA) within six months of the index EMPI. Two groups: HypoR, (defined as peak systolic blood pressure (SBP) less than rest SBP or failure of SBP to raise >20mm Hg during exercise) and no HypoR were studied. Clinical and stress variables were analyzed. Univariate analysis performed using Student t test or chi-square test. Patients were followed up for a mean of 63.2 months (±26.98) for the identification of the first MACE (defined as cardiac death, nonfatal MI, unstable angina, any revascularization, or CVA) and Kaplan Meir analysis was done.
Results: 216 Patients were identified, HypoR (n=61, 28.2%) and No HypoR (n=155). Mean age was 61.4 (±11.4), 71.3% were males, 64.4% had hypertension, 25.5% had DM, 9.7% had EF<40% and 60.2% were using B-blockers with no difference between the two groups. Patients with HypoR were more often Caucasians (82% vs. 61%, p=0.004), had lower mean peak SBP (p<0.001), lower mean peak diastolic blood pressure (p<0.001), lower mean peak heart rates (p<0.001), and lower double product (p<0.001). Both groups had a high but comparable incidence of abnormal scans given the population studied (90% vs. 83% respectively, p=0.163) and comparable high rates of revascularization (71.2% vs. 78% respectively, p=0.31). KM survival curves showed no significant difference between groups for death (p=0.41) and MI (p=0.30) or other MACE, with over 85% event free survival during follow-up period for hard cardiac events (death/MI).
Conclusion: HypoR although a high risk stress test marker for coronary artery disease is not an adverse long term prognosticator once revascularization strategies are accounted for.