Prognostic Implications of Myocardial Perfusion Single-Photon Emission Computed Tomography in the Elderly

Abstract

Background-The goal of this study was to assess the clinical value of stress myocardial perfusion scintigraphy (MPS) in elderly patients (Ն75 years of age). Methods and Results-We followed up 5200 elderly patients (41% exercise) after dual-isotope MPS over 2. 8Ϯ1.7 years (362 cardiac deaths [CDs], 7.0%, 2.6%/y) and a subset with extended follow-up (684 patients for 6.2Ϯ2.9 years; 320 all-cause deaths). Survival modeling of CD revealed that both MPS-measured ischemia and fixed defect added incrementally to pre-MPS data in both adenosine and exercise stress patients. Modeling a subset with gated MPS (nϭ2472) revealed that ejection fraction and perfusion data added incrementally to each other, further enhancing risk stratification. Unadjusted, annualized post-normal MPS CD rate was 1.3% but Ͻ1% in patients with normal rest ECG, exercise stress, or age of 75 to 84 years and was 2.3% to 3.7% in patients Ն85 years of age or undergoing pharmacological stress. However, compared with age-matched US population CD rates (75 to 84 years of age, 1.5%; Ն85 years, 4.8%), normal MPS CD rates were approximately one-third lower than the baseline risk of US individuals (both PϽ0.05). Modeling of all-cause death in 684 patients with extended follow-up revealed that after risk adjustment, an interaction between early treatment and ischemia was present; increasing ischemia was associated with increasing survival with early revascularization, whereas in the setting of little or no ischemia, medical therapy had improved outcomes. Conclusions-Stress MPS effectively stratifies CD risk in elderly patients and may identify optimal post-MPS therapy. CD rates after normal MPS are low in all subsets in relative terms compared with the age-matched US population. (Circulation.

Role of myocardial perfusion scintigraphy in octogenarians: Time for reappraisal?

“…When comparing these two groups, octogenarians had more severe and extensive myocardial ischemia, while coronary artery disease (CAD) was more pronounced and diffuse. Like in previous investigations, [2][3][4][5][6][7] octogenarians had a significantly higher major adverse cardiac event rate than in younger patients during a mean follow-up period of 32 months. Notably, in the current retrospective analysis, 1 the diagnostic accuracy of MPS was similar among both groups (area under the curve (AUC) for, e.g., two or three vessel disease: 0.54 vs 0.58), while the prognostic accuracy was higher or comparable between octogenarians and the younger group for death (hazard ratio (HR):10.7 vs 2.72), myocardial infarction (HR: 1.06 vs 1.24), or their combination (HR: 4.93 vs 1.87).…”

“…Given the steady increase of elderly patients or individuals older than 75 years, MPS is likely to play a more central role in these elderly patients for the detection of hemodynamic and prognostic relevant CAD. 2 Notably, CAD appears to be the prevalent cause of morbidity and mortality in the elderly. 11 While the increasing use of modern coronary revascularization procedures has indeed reduced cardiovascular morbidity and mortality in younger patients, this was not so much observed for the elderly population.…”

“…Advanced CAD in the elderly may frequently manifest as silent ischemia, atypical symptoms, and of a nonspecific deterioration of functional capacity. In this direction, Hachamovitch et al 2 analyzed the role of MPS in 5220 elderly patients to identify individuals at cardiovascular risk over a mean follow-up of 2.8 ± 1.7 years. As regards cardiac deaths, a constant and significantly increase from normal, mildly abnormal, and moderately-to-severely abnormal myocardial perfusion during pharmacologic stress (1.9% vs 2.7% vs 7.8%) or exercise stress (0.7% vs 1.0% vs 2.7%) was observed.…”

Choosing exercise or pharmacologic stress imaging, or exercise ECG testing alone: How to decide

“…5 Similar findings were reported by Hachamovitch et al in elderly patients. 6 The annualized cardiac mortality was 7.8% for patients with moderately abnormal MPI results with pharmacologic stress vs 2.7% with such abnormal results in patients who underwent exercise MPI. Myers et al reported that exercise capacity was a stronger predictor of mortality than cardiovascular risk factors.…”

Adenosine MPS in octogenarians: Looking safely into the future

“…Previous studies investigating the prognostic value of stress imaging in patients aged 70 years and over have shown similar findings although the predictive power of imaging variables and their value relative to other markers of risk differ between studies. [12][13][14] Patient's ability to exercise appears to be an important determinant of these differences. In the very elderly patient with CAD, physical capacity is likely to have wider prognostic implications because of its relation to biological aging and frailty.…”