Combined assessment of left ventricular perfusion and function by gated single-photon emission computed tomography for the risk stratification of high-risk hypertensive patients.
OBJECTIVE
This study was aimed at verifying whether combined information on left ventricular perfusion and function by electrocardiogram-gated single-photon emission computed tomography (SPECT) retains its known prognostic value in patients with systemic hypertension.


METHODS
A total of 415 hypertensive patients underwent rest and stress (exercise in 278 and dipyridamole in 137) gated 99mTc-sestamibi SPECT and prospective follow-up for the composite endpoint of death and acute coronary syndrome. Patients undergoing revascularization were censored. The individual effect of clinical and stress imaging data on outcome was evaluated by Cox regression analysis. Model validation was performed using bootstrap methods adjusted by the degree of optimism in estimates. Survival analysis was performed using the product-limit Kaplan-Meier method.


RESULTS
During a median follow-up of 24 months, 12 cardiac deaths and 32 acute coronary syndromes occurred. After adjusting for the most significant covariates, age [hazard ratio (HR) 1.62, 95% confidence interval (CI) 1.02-2.57], diabetes (HR 7.51, 95% CI 1.61-35.2), summed stress score (HR 2.06, 95% CI 1.07-4), and peak end-systolic volume (HR 3.62, 95% CI 1.35-9.69) were multivariable predictors of outcome. The normal perfusion pattern was associated with a low event rate independently of peak end-systolic volume. Conversely, in the case of moderate to severe perfusion abnormalities, a peak end-systolic volume greater than 74 ml was able to identify an increased risk of adverse outcome. Moreover, peak end-systolic volume was significantly higher among patients who died of a cardiac cause compared with those with different outcomes.


CONCLUSIONS
A combined assessment of left ventricular perfusion and function by gated SPECT significantly improves risk stratification in hypertensive patients.
Cardiology, Department of Medicine and Surgery, University School of Medicine and Centro Cardiologico, Monzino, Milan, Italy.
Riccardo
R
Bigi
Alberto
A
Bestetti
Aldo
A
Strinchini
Antonio
A
Conte
Dario
D
Gregori
Bruno
B
Brusoni
Cesare
C
Fiorentini
D000368:Aged; D001794:Blood Pressure; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D016019:Survival Analysis; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods* / Q000706:statistics & numerical data