Myocardial perfusion imaging in assessing risk of coronary events in patients with systemic lupus erythematosus.

OBJECTIVE: Classic risk factors do not fully account for the increased risk of coronary artery disease (CAD) in systemic lupus erythematosus (SLE), making identification of the subset of patients at risk challenging. In this prospective cohort study we investigated whether myocardial perfusion defects in SLE are predictive of CAD events, independently of traditional Framingham risk factors. METHODS: We performed myocardial perfusion imaging in 122 women with SLE who did not have a history of CAD. Patients had clinical and serologic evaluation, and an assessment of cardiac risk factors. They were then followed for the occurrence of CAD events. Cox regression models were used to determine independent predictors of CAD. RESULTS: Forty-six (37.7%) patients had perfusion defects. Median followup was 8.7 years, during which 15 CAD events occurred (1 myocardial infarction, 14 angina). Cox modeling showed that myocardial perfusion defects are strongly predictive of CAD [hazard ratio (HR) 13.0, 95% CI 2.8 to 60.1, p = 0.001]. Although the 10-year Framingham risk score was significantly predictive of CAD (HR 1.8, 95% CI 1.1 to 2.9, p = 0.01), the risk scores in groups with normal and abnormal scans were similar to the "low-risk" general population. CONCLUSION: In women with SLE, myocardial perfusion defects are strongly and independently predictive of CAD. Our findings suggest that myocardial perfusion imaging to assess risk of future coronary events should be considered in women with SLE.

Positron emission tomography and recovery following revascularization (PARR-1): the importance of scar and the development of a prediction rule for the degree of recovery of left ventricular function.

OBJECTIVES: The aim of this study was to determine whether the extent of viability or scar is important in the amount of recovery of left ventricular (LV) function, and to develop a model for predicting recovery after revascularization that could be tested in a randomized trial. BACKGROUND: F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) is used to define viable myocardium in patients with coronary artery disease (CAD) and severe LV dysfunction and to guide revascularization decisions. Whether this approach improves clinical outcomes has not been tested in a randomized trial. Before doing so, an objective model for prediction of recovery is required. METHODS: A total of 82 patients with CAD and an ejection fraction (EF) < or =35% had FDG PET perfusion imaging before revascularization. Complete follow-up was available on 70 patients (86%). Patients had radionuclide angiograms at baseline and three months post-revascularization. RESULTS: Diabetes (p = 0.029), time to operation (p = 0.008), and scar score (p = 0.001) were significant independent predictors of the change in EF. Previous coronary artery bypass graft confounded the effect of age. There was a significant interaction between the perfusion tracer used and mismatch score (p = 0.02). The multivariable prediction model incorporating PET and clinical variables had a goodness of fit with p = 0.001. Across tertiles of scar scores (I, small: 0% to 16%; II, moderate: 16% to 27.5%; III, large: 27.5% to 47%), the changes in EFs were 9.0 +/- 1.9%, 3.7 +/- 1.6%, and 1.3 +/- 1.5% (p = 0.003: I vs. III), respectively. CONCLUSIONS: In patients with severe LV dysfunction, the amount of scar was a significant independent predictor of LV function recovery after revascularization. A combination of PET and clinical parameters predicts the degree of recovery. This model is being applied in a large randomized controlled trial to determine the effectiveness of therapy guided by FDG PET.

The relationships of left ventricular ejection fraction, end-systolic volume index and infarct size to six-month mortality after hospital discharge following myocardial infarction treated by thrombolysis.

OBJECTIVES: We sought to relate left ventricular ejection fraction (EF), end-systolic volume index (ESVI) and infarct size (IS), as measured in a single randomized trial, to six-month mortality after myocardial infarction (MI) treated with thrombolysis. BACKGROUND: These three prognostic indicators have never been compared in the same study group. METHODS: Radionuclide angiographic and single-photon emission computed tomographic sestamibi measurements of IS were performed in 1,194 and 1,181 patients, respectively, of the 2,948 patients enrolled in the Collaborative Organization for RheothRx Evaluation (CORE) trial. Ejection fraction, ESVI and IS, as measured by central laboratories in these radionuclide substudies, were tested for their association with six-month mortality. RESULTS: Ejection fraction (n = 1,137; p < 0.0001), ESVI (n = 945; p = 0.055) and IS (n = 1,164; p = 0.03) were all associated with six-month mortality. Each of these measurements was significantly correlated with the other two, regardless of MI location. In an "overlap" group of 753 patients (25.5% of the population; 13 deaths) in whom all three measurements were available, EF (p = 0.001) was a stronger predictor than ESVI (p = 0.005) or IS (p = 0.01). Neither of the other two measurements added independent prognostic information. The highest risk subgroup (EF < 30%) had an 11% six-month mortality, but comprised only 95 patients (8.3%). CONCLUSIONS: Ejection fraction, ESVI and IS measurements performed one to two weeks after MI can each predict six-month mortality. Ejection fraction was superior to the other two measurements. However, this study had limited power to detect independent significance of ESVI or IS.