Comparison of the Short-Term Survival Benefit Associated With Revascularization Compared With Medical Therapy in Patients With No Prior Coronary Artery Disease Undergoing Stress Myocardial Perfusion Single Photon Emission Computed Tomography

Abstract

Background-The relationship between the amount of inducible ischemia present on stress myocardial perfusion single photon emission computed tomography (myocardial perfusion stress [MPS]) and the presence of a short-term survival benefit with early revascularization versus medical therapy is not clearly defined. Methods and Results-A total of 10 627 consecutive patients who underwent exercise or adenosine MPS and had no prior myocardial infarction or revascularization were followed up (90.6% complete; mean: 1.9Ϯ0.6 years). Cardiac death occurred in 146 patients (1.4%). Treatment received within 60 days after MPS defined subgroups undergoing revascularization (671 patients, 2.8% mortality) or medical therapy (MT) (9956 patients, 1.3% mortality; Pϭ0.0004).To adjust for nonrandomization of treatment, a propensity score was developed using logistic regression to model the decision to refer to revascularization. This model ( 2 ϭ1822, c indexϭ0.94, PϽ10 Ϫ7 ) identified inducible ischemia and anginal symptoms as the most powerful predictors (83%, 6% of overall 2 ) and was incorporated into survival models. On the basis of the Cox proportional hazards model predicting cardiac death ( 2 ϭ539, PϽ0.0001), patients undergoing MT demonstrated a survival advantage over patients undergoing revascularization in the setting of no or mild ischemia, whereas patients undergoing revascularization had an increasing survival benefit over patients undergoing MT when moderate to severe ischemia was present. Furthermore, increasing survival benefit for revascularization over MT was noted in higher risk patients (elderly, adenosine stress, and women, especially those with diabetes). Conclusions-Revascularization compared with MT had greater survival benefit (absolute and relative) in patients with moderate to large amounts of inducible ischemia. These findings have significant consequences for future approaches to post-single photon emission computed tomography patient management if confirmed by prospective evaluations.

Guidelines on myocardial revascularization

“…The adverse impact of demonstrable ischaemia on clinical outcome [death, myocardial infarction (MI), ACS, occurrence of angina] has been well recognized for over two decades [13,38]. While symptomatic patients with no or little evidence of ischaemia have no prognostic benefit from revascularization, asymptomatic patients with a significant mass of ischaemic myocardium do [13,38].…”

PET imaging of cardiac hypoxia: Opportunities and challenges

“…Even though these data show a correlation between degree of ischemia and outcome [7], and provide a threshold for the appropriateness of revascularization, it is impossible to determine the clinical significance of reduced blood flow for an individual patient [8]. While generating fully quantitative data (i.e.…”

Cardiac hybrid imaging: state-of-the-art

“…Hybrid imaging is a completely non-invasive approach to coronary artery disease which allows obtaining important information prior to any invasive procedure and provides the detailed information for evidence driven intervention targeting relevant lesion only. Although the CT part of hybrid imaging has excellent abilities in ruling out hemodynamic relevant coronary artery disease, an abnormal CTCA -like an abnormal conventional angiography study -is a poor predictor of ischemia, and further perfusion imaging testing is warranted to identify those patients who might benefit from a revascularization procedure (36,37) and those in whom conservative management and risk modification may be justified (38) Results from a first multicenter study underline the value of a combined functional and anatomical approach even without hybrid imaging showing that this combination allows improved risk stratification (41). The clinical usefulness in terms of impact on treatment strategy and subsequently on outcome by hybrid imaging remains, however, to be determined in prospective and long-term studies.…”