Aim: Hybrid SPECT-CT tomographs offer the opportunity to simul- taneously evaluate both functional (MPI) and morphoanatomical (CCS) aspects of the atherosclerosis. The aim of this study is to assess the additional prognostic value of CCS in adjunct to MPI in the evaluation of patients with intermediate-risk of CAD. Materials and Methods: Study population consisted of 367 prospec- tive patients who were clinically scheduled for MPI and classified at intermediate risk on the basis of the Framingham Risk Score. All subjects underwent contextual rest sestamibi MPI and CCS evaluation as a part of a standard two-days stress-rest MPI protocol. Studies were acquired with an hybrid Symbia T2 tomograph (Siemens). Summed Stress Scores (SSS) and Agatston data were calculated for all patients and MPI studies were considered ‘‘positive’’ (+) if SSS [ 3. Subjects were divided into four groups on the basis of tests results: MPI- and CCS \ 400 (group A); MPI- and CCS C 400 (group B); MPI+and CCS \ 400 (group C); and MPI+ and CCS C 400 (group D). Results: Fifteen patients were excluded because of sub-optimal quality of imaging and other 22 subjects did not complete the follow-up. The remaining 330 patients (216 men, mean age 67 ± 12 years) were prospectively followed for an average of 63 ± 9 months and the out- come events considered were: cardiac death, non-fatal myocardial infarction, hospitalization for unstable angina and late ([90 days) coronary revascularization. Group A consisted of 126 patients, group B of 58, group C of 32 and group D of 114. The cardiac event rate in the study population was 2.7%/year. Annual event rates for overall cardiac events in group A, B, C and D were 0.3, 1.4, 4.4 and 5.6%/year respectively. Patients with a normal MPI had higher survival free of cardiac events (P \ .01); additionally an increase in global chi-square in predicting all cardiac events occurred when CCS data were added to MPI information. Kaplan-Meier curves showed a significant difference in event-free survival at 5 years in the four groups. Conclusions: Although this study suffers from several limitations it outlines that an ‘‘hybrid’’ approach, combining an anatomic assessment of coronary atherosclerotic plaque burden (which probably better estimates longer-term prognosis) with a functional evaluation of myocardial ische- mia (more closely related to a ‘‘short-term risk’’) may contribute to refine temporal risk stratification among subjects at intermediate likelihood of CAD. Multicenter trials are mandatory to confirm these preliminary findings and to assess their potential impact in larger clinical settings.
Simultaneous evaluation of myocardial perfusion imaging (MPI) and coronary calcium score (CCS) in patients with intermediate likelihood of CAD: A 5 year follow-up study
CITTANTI, Corrado;
2013
Abstract
Aim: Hybrid SPECT-CT tomographs offer the opportunity to simul- taneously evaluate both functional (MPI) and morphoanatomical (CCS) aspects of the atherosclerosis. The aim of this study is to assess the additional prognostic value of CCS in adjunct to MPI in the evaluation of patients with intermediate-risk of CAD. Materials and Methods: Study population consisted of 367 prospec- tive patients who were clinically scheduled for MPI and classified at intermediate risk on the basis of the Framingham Risk Score. All subjects underwent contextual rest sestamibi MPI and CCS evaluation as a part of a standard two-days stress-rest MPI protocol. Studies were acquired with an hybrid Symbia T2 tomograph (Siemens). Summed Stress Scores (SSS) and Agatston data were calculated for all patients and MPI studies were considered ‘‘positive’’ (+) if SSS [ 3. Subjects were divided into four groups on the basis of tests results: MPI- and CCS \ 400 (group A); MPI- and CCS C 400 (group B); MPI+and CCS \ 400 (group C); and MPI+ and CCS C 400 (group D). Results: Fifteen patients were excluded because of sub-optimal quality of imaging and other 22 subjects did not complete the follow-up. The remaining 330 patients (216 men, mean age 67 ± 12 years) were prospectively followed for an average of 63 ± 9 months and the out- come events considered were: cardiac death, non-fatal myocardial infarction, hospitalization for unstable angina and late ([90 days) coronary revascularization. Group A consisted of 126 patients, group B of 58, group C of 32 and group D of 114. The cardiac event rate in the study population was 2.7%/year. Annual event rates for overall cardiac events in group A, B, C and D were 0.3, 1.4, 4.4 and 5.6%/year respectively. Patients with a normal MPI had higher survival free of cardiac events (P \ .01); additionally an increase in global chi-square in predicting all cardiac events occurred when CCS data were added to MPI information. Kaplan-Meier curves showed a significant difference in event-free survival at 5 years in the four groups. Conclusions: Although this study suffers from several limitations it outlines that an ‘‘hybrid’’ approach, combining an anatomic assessment of coronary atherosclerotic plaque burden (which probably better estimates longer-term prognosis) with a functional evaluation of myocardial ische- mia (more closely related to a ‘‘short-term risk’’) may contribute to refine temporal risk stratification among subjects at intermediate likelihood of CAD. Multicenter trials are mandatory to confirm these preliminary findings and to assess their potential impact in larger clinical settings.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
