Long-Term Association of Dipyridamole Stress Myocardial Contrast Echocardiography versus Single-Photon Emission Computed Tomography with Clinical Outcomes in Patients with Known or Suspected Coronary Artery Disease.

BACKGROUND: Single-photon emission computed tomography (SPECT) is a well-established method to evaluate patients with coronary artery disease. Myocardial contrast echocardiography (MCE) is an imaging technique that allows the assessment of myocardial perfusion in real time. Previous research has shown that vasodilator MCE is superior to SPECT for the prediction of hard events. The aim of this study was to investigate the long-term association of SPECT and MCE with clinical outcomes in patients with known or suspected coronary artery disease. METHODS: Accordingly, 258 patients who underwent MCE and SPECT as part of multicenter studies performed prospectively were followed up for hard events (all-cause mortality and nonfatal myocardial infarction). The mean age was 63.4 ± 5.5 years, 186 (72.1%) were men, and 32 (12.4%) had left ventricular systolic dysfunction. We calculated the ratio of the number of abnormal segments (at rest and/or stress) to the total number of segments expressed as MCE and SPECT indices. RESULTS: Over a mean follow-up period of 80.4 ± 6.1 months, 46 patients had hard events. MCE and SPECT indices were associated with all-cause mortality on univariate analysis (P = .008 and P = .035, respectively) but only MCE index was independently associated with hard events (hazard ratio, 4.24; 95% CI, 1.27-14.15; P = .019), beyond clinical data and left ventricular function, and independently associated with hard cardiac events (hazard ratio, 4.78; 95% CI, 1.06-21.59; P = .042). CONCLUSIONS: MCE but not SPECT showed a long-term association with outcome. These results thus favor the routine use of MCE in the long-term assessment of patients with known or suspected coronary artery disease.

The clinical impact of contemporary stress echocardiography in morbid obesity for the assessment of coronary artery disease.

OBJECTIVE: Non-invasive cardiac imaging may suffer from poor image quality in morbidly obese individuals. This study aimed to determine the clinical value of contemporary stress echocardiography (SE) in morbidly obese patients referred for assessment of suspected coronary artery disease (CAD). METHODS: This prospective, multicentre observational study was conducted in two district hospitals and one tertiary centre in London, UK. Individuals with body mass index ≥35 kg/m(2) referred for SE were evaluated. The percentage of patients with obstructive CAD on coronary angiography, following abnormal SE, was assessed. Patient outcomes were determined with follow-up for the composite end-point of all-cause mortality, myocardial infarction and late revascularisation. RESULTS: Over a 13-month period, 209 morbidly obese patients underwent SE, and contrast agent was used in 96% of patients. A diagnostic result was obtained in 200/209 (96%) patients. Of 32 (15%) patients with inducible ischaemia, 25 underwent angiography, 22 (88%) had corresponding significant CAD and, of these, 16 (77%) underwent revascularisation. Conversely, only 2/157 patients (1.3%) with normal SE underwent angiography, and none underwent revascularisation. Over a mean follow-up period of 17.8±5.4 months, there were nine events. The annualised cardiac event rate after a normal SE was 0.95%. Events were more frequent in patients with inducible ischaemia versus those without ischaemia (5/32 (15.6%) vs 4/153 (2.6%); p=0.002). Ejection fraction <50% (HR 9.5; 95% CI 2.4 to 38.0; p=0.002) and inducible ischaemia (HR 9.4; 95% CI 2.5 to 35.8; p=0.001) were predictors of outcome on univariable Cox regression analysis. CONCLUSIONS: Contemporary SE has excellent feasibility and positive predictive value and resulted in appropriate risk stratification of symptomatic patients with significant obesity. A normal SE portends an excellent outcome over the short-intermediate term in this high-risk patient population.

Timing of clopidogrel loading before percutaneous coronary intervention in clopidogrel-naive patients with stable or unstable angina: a comparison of two strategies.

BACKGROUND: Clopidogrel-naive patients subjected to coronary angiography may be candidates for percutaneous coronary intervention (PCI). Clopidogrel loading with 600 mg at least 2 hours before the procedure is advised for such patients. However, there is no direct evidence that delaying PCI for 2 hours after clopidogrel loading is superior to ad hoc PCI. METHODS: After coronary angiography, clopidogrel-naive patients (N = 199) with stable or unstable angina, candidates for PCI, were loaded with 900 mg of clopidogrel and then randomized to ad hoc PCI (ad hoc group, n = 103) or delayed PCI 2 hours after loading (delayed group, n = 96). Combined primary end point was death/periprocedural myocardial infarction (MI)/stroke/reintervention within 30 days post-PCI. Secondary end points were periprocedural MI; periprocedural creatine kinase-MB elevation >3 x upper limit of normal; any periprocedural increase of creatine kinase-MB, troponin-I, or myoglobin above upper limit of normal; Thrombolysis in Myocardial Infarction flow <3 after PCI; thrombocytopenia with platelet count of <70,000/mL; major bleeding defined according to the Thrombolysis in Myocardial Infarction criteria; and elevation of high-sensitivity C-reactive protein and soluble P selectin. RESULTS: Primary end point occurred in 12.6% ad hoc group versus 15.6% delayed group patients (P = .34). High-sensitivity C-reactive protein increased in both groups post-PCI (analysis of variance P < .0001) without difference between groups (P = .5). Major bleeding occurred in 2.9% ad hoc group versus 3.1% delayed group patients (P = .9). No significant difference was observed in any other secondary end point. CONCLUSIONS: In clopidogrel-naive patients, a strategy of delaying PCI for 2 hours after high-dose clopidogrel loading does not seem to confer any benefit compared to ad hoc PCI.