Aman Amanullah

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

Background— The goal of this study was to assess the clinical value of stress myocardial perfusion scintigraphy (MPS) in elderly patients (≥75 years of age). Methods and Results— We followed up 5200 elderly patients (41% exercise) after dual-isotope MPS over 2.8±1.7 years (362 cardiac deaths [CDs], 7.0%, 2.6%/y) and a subset with extended follow-up (684 patients for 6.2±2.9 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 (n=2472) 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 <1% in patients with normal rest ECG, exercise stress, or age of 75 to 84 years and was 2.3% to 3.7% in patients ≥85 years of age or undergoing pharmacological stress. However, compared with age-matched US population CD rates (75 to 84 years of age, 1.5%; ≥85 years, 4.8%), normal MPS CD rates were approximately one-third lower than the baseline risk of US individuals (both P<0.05). 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.

Influence of Diabetes Mellitus on Prognostic Utility of Imaging of Myocardial Sympathetic Innervation in Heart Failure Patients

Background—Patients with diabetes mellitus have accelerated progression of heart failure and often have impaired cardiac sympathetic innervation. The present study examines the implications for heart failure progression of cardiac sympathetic denervation, assessed by I-123 metaiodobenzylguanidine imaging, in diabetic compared with nondiabetic subjects. Methods and Results—We evaluated 343 diabetic and 618 nondiabetic subjects with New York Heart Association class II or III heart failure and a left ventricular ejection fraction ⩽35% over a median follow-up of 17 months. A multivariable Cox proportional hazards model was used to examine the influence of clinical variables, b-type natriuretic peptide, plasma norepinephrine, left ventricular ejection fraction, and I-123 metaiodobenzylguanidine imaging parameters on time to a heart failure event. The late heart-to-mediastinum (H/M) ratio and the interaction term of diabetes mellitus with the prospectively selected late H/M ratio <1.6 were independent predictors of heart failure progression, providing incremental prognostic information beyond that available from all other variables. In diabetic subjects, late H/M ratio <1.6 was associated with a 2.99-fold greater 2-year rate of heart failure progression (33.5%) than late H/M ratio ≥1.6 (11.2% event rate). Conclusions—The combination of diabetes mellitus and I-123 metaiodobenzylguanidine H/M ratio is an independent predictor of heart failure progression, confirming the high risk of diabetic subjects with impaired cardiac sympathetic nerve function. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00126438 and NCT00126425.

Incidence, predictors, and outcomes of gastrointestinal bleeding in patients on dual antiplatelet therapy with aspirin and clopidogrel.

Objectives The benefits of dual antiplatelet therapy are counterbalanced by the increased incidence of gastrointestinal (GI) complications. The aim of this study was to determine the frequency of GI bleeding, identify the predictors associated with the increased bleeding, and determine the short-term and long-term outcomes. Methods This was an observational, case-control cohort study carried out at the Albert Einstein Medical Center. It included all patients who had a drug-eluting stent implanted between May 2003 and April 2007. A total of 1852 patients were identified; of these 50 patients were readmitted for a GI bleed. A control group of 202 patients who did not have any evidence of GI bleeding were compared with the original group. All data were expressed as mean±SD. The baseline clinical characteristics between the 2 groups were compared using the t test and the Fisher exact test. Multivariate analysis was used to determine the predictors of GI bleeding. Results The rate of GI bleeding was 2.7%. The mean age in the group with GI bleeding was 70.9±12.2 years, whereas in the group without GI bleeding it was 66.5±12.8 years (P<0.05). The majority of the patients presented with melena (40%). Gastritis and gastric ulcers were the most common findings seen in 49% of the patients on endoscopy. On multivariate logistic regression analysis, a history of GI bleeding was the most important independent predictor of future GI bleeding (P<0.001), whereas the use of statins was found to be protective (95% confidence interval, 0.13-0.48; P<0.001) against future GI bleeding. The 30-day mortality rate in the GI bleeding and control groups was 3.7% and 0%, respectively (P<0.01), whereas in the corresponding 1 year the mortality rate was 18.9% and 0%, respectively (P<0.001). Conclusions The rate of GI bleeding in patients on dual antiplatelet therapy is low. Earlier history of GI bleeding is the most significant multivariate predictor of future GI bleeding whereas statins seemed to be protective. Patients with GI bleeding have increased short-term and long-term mortality; thereby a history of earlier GI bleeding needs to be assessed carefully before starting dual antiplatelet therapy. This may play a vital role in the selection of therapeutic strategies in these patients.

Regional left ventricular function does not predict survival in ischaemic cardiomyopathy after cardiac surgery

Objectives To define the prognostic contribution of global and regional left ventricular (LV) function measurements in patients with ischaemic cardiomyopathy randomised to coronary artery bypass graft surgery (CABG) with (n=501) or without (n=499) surgical ventricular reconstruction (SVR). Methods Novel multivariable methods to analyse global and regional LV systolic function were used to better formulate prediction models for long-term mortality following CABG with or without SVR in the entire cohort of 1000 randomised SVR hypothesis patients. Key clinical variables were included in the analysis. Regional function was classified according to the discreteness of anteroapical hypokinesia and akinesia into those most likely to benefit from SVR, those least likely and those felt to have intermediate likelihood of benefit from SVR. Results The most prognostic clinical variables identified in multivariable models include creatinine, LV end-systolic volume index (ESVI), age and NYHA (New York Heart Association) class. Addition of LV ejection fraction, LV end-diastolic volume index and regional function assessment did not contribute additional power to the model. Subgroup analysis based on regional function did not identify a cohort in which SVR improved mortality. Conclusions ESVI is the single parameter of LV function most predictive of mortality in patients with LV systolic dysfunction following CABG with or without SVR in multivariable models that include all key clinical and LV systolic function parameters. Assessment of regional cardiac function does not enhance prediction of mortality nor identify a subgroup for which SVR improves mortality. These results do not support elective addition of LV reconstruction surgery in patients undergoing CABG. Trial registration number NCT00023595.