Patient management after noninvasive cardiac imaging results from SPARC (Study of myocardial perfusion and coronary anatomy imaging roles in coronary artery disease).

OBJECTIVES: This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. BACKGROUND: Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. METHODS: We assessed the 90-day post-test rates of catheterization and medication changes in a prospective registry of 1,703 patients without a documented history of coronary artery disease and an intermediate to high likelihood of coronary artery disease undergoing cardiac single-photon emission computed tomography, positron emission tomography, or 64-slice coronary computed tomography angiography. RESULTS: Baseline medication use was relatively infrequent. At 90 days, 9.6% of patients underwent catheterization. The rates of catheterization and medication changes increased in proportion to test abnormality findings. Among patients with the most severe test result findings, 38% to 61% were not referred to catheterization, 20% to 30% were not receiving aspirin, 35% to 44% were not receiving a beta-blocker, and 20% to 25% were not receiving a lipid-lowering agent at 90 days after the index test. Risk-adjusted analyses revealed that compared with stress single-photon emission computed tomography or positron emission tomography, changes in aspirin and lipid-lowering agent use was greater after computed tomography angiography, as was the 90-day catheterization referral rate in the setting of normal/nonobstructive and mildly abnormal test results. CONCLUSIONS: Overall, noninvasive testing had only a modest impact on clinical management of patients referred for clinical testing. Although post-imaging use of cardiac catheterization and medical therapy increased in proportion to the degree of abnormality findings, the frequency of catheterization and medication change suggests possible undertreatment of higher risk patients. Patients were more likely to undergo cardiac catheterization after computed tomography angiography than after single-photon emission computed tomography or positron emission tomography after normal/nonobstructive and mildly abnormal study findings. (Study of Perfusion and Anatomy's Role in Coronary Artery [CAD] [SPARC]; NCT00321399).

Off-pump and on-pump coronary artery bypass grafting are associated with similar graft patency, myocardial ischemia, and freedom from reintervention: long-term follow-up of a randomized trial.

BACKGROUND: The Surgical Management of Arterial Revascularization Therapies trial was conceived to rigorously compare completeness of revascularization, clinical outcomes and resource utilization in unselected patients referred for elective, primary coronary artery bypass grafting randomly assigned to undergo off-pump (OPCAB) or conventional on-pump coronary artery bypass grafting using cardiopulmonary bypass (CPB). The goal of this follow-up study was to compare long-term survival, graft patency, myocardial ischemia, and clinical outcomes among survivors who volunteered to return for clinical evaluation and imaging studies. METHODS: Two hundred unselected patients with multivessel coronary artery disease were randomly assigned to OPCAB or CPB coronary artery bypass grafting between March 2000 and August 2001. All-cause mortality was determined by individual patient contact and referencing the Social Security Death Master File. Of 140 survivors, 87 volunteered to return after a minimum of 6.8 years (maximum, 8.4 years; mean, 7.5 years) for assessment of graft patency (computed tomographic angiography) and myocardial ischemia (cardiac positron emission tomography and 12-lead electrocardiogram). Age at follow-up ranged from 38 to 90 years (mean, 68 years). RESULTS: There were 26 deaths from all causes among OPCAB patients and 31 among CPB patients as of March 30, 2009. Graft patency was similar between groups among 622 grafts assessed by angiography before hospital discharge (99% OPCAB versus 97.7% CPB; p=0.22, Fisher's exact test), among 511 grafts assessed by angiography at 1 year (93.6% OPCAB versus 95.8% CPB; p=0.33), and among 190 grafts assessed by computed tomographic angiography at late follow-up (76% OPCAB versus 83.5% CPB; p=0.44). Twelve of 34 OPCAB (35.3%) and 16 of 39 CPB patients (41.0%) had any ischemia on positron emission tomography scanning (p=0.62). Four OPCAB patients (11.8%) and 9 CPB patients (23.1%) had an ischemic region in excess of 10% of myocardium (p=0.21). At late follow-up, recurrent angina had occurred in 11 of 43 (25.6%) OPCAB patients and 5 of 44 (11.4%) CPB patients (p=0.09). Percutaneous reintervention had been performed at the discretion of blinded local cardiologists in 1 of 43 (2.3%) OPCAB patients and 1 of 44 (2.3%) CPB patients (p=1.0). No patient in either group has undergone repeat CABG. CONCLUSIONS: In this randomized trial, off-pump and on-pump coronary artery bypass grafting were associated with similar early and late graft patency, incidence of recurrent or residual myocardial ischemia, need for reintervention, and long-term survival.

Myocardial viability assessment by PET: (82)Rb defect washout does not predict the results of metabolic-perfusion mismatch.

UNLABELLED: PET is a sensitive technique for the identification of viable myocardial tissue in patients with coronary disease. Metabolic assessment with (18)F-FDG is considered the gold standard for assessment of viability before surgical revascularization. Prior research has suggested that viability may be assessed with washout of (82)Rb between early and late resting images. Our objective was to determine whether assessment of myocardial viability with (82)Rb washout is reliable when compared with PET using (18)F-FDG. METHODS: We performed PET for 194 patients referred for PET (18)F-FDG/(82)Rb to assess viability for clinical indications. We included 151 patients with resting defects >10% of the left ventricle (LV) (n = 159 defects). Patients with smaller resting (82)Rb defects (<10% LV) were excluded for the purpose of this study. PET images acquired with (82)Rb and (18)F-FDG defined viability by the mismatch between metabolism and perfusion ((18)F-FDG >125% of (82)Rb uptake in the (82)Rb defect). Evidence of viability with (82)Rb was assessed by the presence of (i) severity: (82)Rb counts in the defect >50% of (82)Rb in the normal zone of the resting PET images; (ii) washout: decrease of (82)Rb counts in the defect from early to late resting (82)Rb images <17% between the first 90-s image and the final 300-s image; or (iii) combined severity and washout criteria, which required positive criteria for (i) and (ii) to indicate viability. RESULTS: Prevalence of viability by (18)F-FDG/(82)Rb criteria was 50% (n = 79). Severity criteria yielded a sensitivity of 76% and a specificity of 17%, washout criteria yielded a sensitivity of 81% and a specificity of 23%, and both criteria had a sensitivity of 63% and a specificity of 32%. Positive and negative predictive values were poor for all criteria. No correlation existed between (82)Rb washout and (18)F-FDG-(82)Rb mismatch (r(2) = 0.00). Multiple receiver-operating-characteristic plots showed very poor discrimination despite varying criteria for viability by (82)Rb (severity from 50% to 60% of normal zone, washout from 12% to 17%). CONCLUSION: (82)Rb washout from early to late resting images, combined with quantitative severity of the resting (82)Rb defect, did not yield results equivalent to PET (18)F-FDG-(82)Rb mismatch and may not accurately assess myocardial viability.