Saadat A. Khan

Prevalence and Prognostic Significance of Left Ventricular Noncompaction in Patients Referred for Cardiac Magnetic Resonance ImagingCLINICAL PERSPECTIVE

Background— Presence of prominent left ventricular trabeculation satisfying criteria for left ventricular noncompaction (LVNC) on routine cardiac magnetic resonance examination is frequently encountered; however, the clinical and prognostic significance of these findings remain elusive. This registry aimed to assess LVNC prevalence by 4 current criteria and to prospectively evaluate an association between diagnosis of LVNC by these criteria and adverse events. Methods and Results— There were 700 patients referred for cardiac magnetic resonance: 42% were women, median age was 70 years (range, 45–71 years), mean left ventricular ejection fraction was 51% (±17%), and 32% had late gadolinium enhancement on cardiac magnetic resonance. The cohort underwent diagnostic assessment for LVNC by 4 separate imaging criteria—referenced by their authors as Petersen, Stacey, Jacquier, and Captur, with LVNC prevalence of 39%, 23%, 25% and 3%, respectively. Primary clinical outcome was combined end point of time to death, ischemic stroke, ventricular tachycardia/ventricular fibrillation, and heart failure hospitalization. Secondary clinical outcomes were (1) all-cause mortality and (2) time to the first occurrence of any of the following events: cardiac death, ischemic stroke, ventricular tachycardia/ventricular fibrillation, or heart failure hospitalization. During a median follow-up of 7 years, there were no statistically significant differences in assessed outcomes noted between patients with and without LVNC irrespective of the applied criteria. Conclusions— Current criteria for the diagnosis of LVNC leads to highly variable disease prevalence in patients referred for cardiac magnetic resonance. The diagnosis of LVNC, by any current criteria, was not associated with adverse clinical events on nearly 7 years of follow-up. Limited conclusions can be made for Captur criteria due to low observed prevalence.

Right Ventricular Dysfunction Impairs Effort Tolerance Independent of Left Ventricular Function Among Patients Undergoing Exercise Stress Myocardial Perfusion ImagingCLINICAL PERSPECTIVE

Background—Right ventricular (RV) and left ventricular (LV) function are closely linked due to a variety of factors, including common coronary blood supply. Altered LV perfusion holds the potential to affect the RV, but links between LV ischemia and RV performance, and independent impact of RV dysfunction on effort tolerance, are unknown. Methods and Results—The population comprised 2051 patients who underwent exercise stress myocardial perfusion imaging and echo (5.5±7.9 days), among whom 6% had echo-evidenced RV dysfunction. Global summed stress scores were ≈3-fold higher among patients with RV dysfunction, attributable to increments in inducible and fixed LV perfusion defects (all P⩽0.001). Regional inferior and lateral wall ischemia was greater among patients with RV dysfunction (both P<0.01), without difference in corresponding anterior defects (P=0.13). In multivariable analysis, inducible inferior and lateral wall perfusion defects increased the likelihood of RV dysfunction (both P<0.05) independent of LV function, fixed perfusion defects, and pulmonary artery pressure. Patients with RV dysfunction demonstrated lesser effort tolerance whether measured by exercise duration (6.7±2.8 versus 7.9±2.9 minutes; P<0.001) or peak treadmill stage (2.6±0.9 versus 3.1±1.0; P<0.001), paralleling results among patients with LV dysfunction (7.0±2.9 versus 8.0±2.9; P<0.001|2.7±1.0 versus 3.1±1.0; P<0.001 respectively). Exercise time decreased stepwise in relation to both RV and LV dysfunction (P<0.001) and was associated with each parameter independent of age or medication regimen. Conclusions—Among patients with known or suspected coronary artery disease, regional LV ischemia involving the inferior and lateral walls confers increased likelihood of RV dysfunction. RV dysfunction impairs exercise tolerance independent of LV dysfunction.

Right atrial volume by cardiovascular magnetic resonance predicts mortality in patients with heart failure with reduced ejection fraction

Background Right Atrial Volume Index (RAVI) measured by echocardiography is an independent predictor of morbidity in patients with heart failure (HF) with reduced ejection fraction (HFrEF). The aim of this study is to evaluate the predictive value of RAVI assessed by cardiac magnetic resonance (CMR) for all-cause mortality in patients with HFrEF and to assess its additive contribution to the validated Meta-Analysis Global Group in Chronic heart failure (MAGGIC) score. Methods and results We identified 243 patients (mean age 60 ± 15; 33% women) with left ventricular ejection fraction (LVEF) ≤ 35% measured by CMR. Right atrial volume was calculated based on area in two- and four -chamber views using validated equation, followed by indexing to body surface area. MAGGIC score was calculated using online calculator. During mean period of 2.4 years 33 patients (14%) died. The mean RAVI was 53 ± 26 ml/m2; significantly larger in patients with than without an event (78.7±29 ml/m2 vs. 48±22 ml/m2, p<0.001). RAVI (per ml/m2) was an independent predictor of mortality [HR = 1.03 (1.01–1.04), p = 0.001]. RAVI has a greater discriminatory ability than LVEF, left atrial volume index and right ventricular ejection fraction (RVEF) (C-statistic 0.8±0.08 vs 0.55±0.1, 0.62±0.11, 0.68±0.11, respectively, all p<0.02). The addition of RAVI to the MAGGIC score significantly improves risk stratification (integrated discrimination improvement 13%, and category-free net reclassification improvement 73%, both p<0.001). Conclusion RAVI by CMR is an independent predictor of mortality in patients with HFrEF. The addition of RAVI to MAGGIC score improves mortality risk stratification.

Review and Analysis of Publication Trends over Three Decades in Three High Impact Medicine Journals

Context Over the past three decades, industry sponsored research expanded in the United States. Financial incentives can lead to potential conflicts of interest (COI) resulting in underreporting of negative study results. Objective We hypothesized that over the three decades, there would be an increase in: a) reporting of conflict of interest and source of funding; b) percentage of randomized control trials c) number of patients per study and d) industry funding. Data sources and Study Selection Original articles published in three calendar years (1988, 1998, and 2008) in The Lancet, New England Journal of Medicine and Journal of American Medical Association were collected. Data Extraction Studies were reviewed and investigational design categorized as prospective and retrospective clinical trials. Prospective trials were categorized into randomized or non-randomized and single-center or multi-center trials. Retrospective trials were categorized as registries, meta-analyses and other studies, mostly comprising of case reports or series. Study outcomes were categorized as positive or negative depending on whether the pre-specified hypothesis was met. Financial disclosures were researched for financial relationships and profit status, and accordingly categorized as government, non-profit or industry sponsored. Studies were assessed for reporting COI. Results 1,671 original articles were included in this analysis. Total number of published studies decreased by 17% from 1988 to 2008. Over 20 year period, the proportion of prospective randomized trials increased from 22 to 46% (p < 0.0001); whereas the proportion of prospective non-randomized trials decreased from 59% to 27% (p < 0.001). There was an increase in the percentage of prospective randomized multi-center trials from 11% to 41% (p < 0.001). Conversely, there was a reduction in non-randomized single-center trials from 47% to 10% (p < 0.001). Proportion of government funded studies remained constant, whereas industry funded studies more than doubled (17% to 40%; p < 0.0001). The number of studies with negative results more than doubled (10% to 22%; p<0.0001). While lack of funding disclosure decreased from 35% to 7%, COI reporting increased from 2% to 84% (p < 0.0001). Conclusion Improved reporting of COI, clarity in financial sponsorship, increased publication of negative results in the setting of larger and better designed clinical trials represents a positive step forward in the scientific publications, despite the higher percentage of industry funded studies.

EFFECT OF COFFEE OR TEA CONSUMPTION ON MORTALITY AND MORBIDITY: A NETWORK META-ANALYSIS OF 58 STUDIES

Tea and coffee are the primary sources of caffeine in the world. Previous studies and meta-analyses suggested a U-shaped relationship between morbidity and coffee dose. On other hand recent large epidemiological study favored tea over coffee for morbidity prevention. We aimed to compare health

Importance of papillary muscle infarction detected by cardiac magnetic resonance imaging in predicting cardiovascular events

BACKGROUND Recent studies suggest that papillary muscle infarction (PMI) following recent myocardial infarction (MI) correlates with adverse cardiovascular outcomes. The purpose of this study is to determine the prevalence and prognostic significance of PMI by cardiac magnetic resonance (CMR) in a large cohort of patients. METHODS Retrospective study of patients who underwent CMR between January 2007 and December 2009 were evaluated for the presence of PMI in one or both of the left ventricle papillary muscles. The primary outcome was a time to a combined endpoint of all-cause mortality and worsening heart failure. Secondary outcomes were time to individual components of the combined outcome. RESULTS 419 patients were included in our analysis, 232 patients (55%) had ischemic cardiomyopathy. Patients were followed at six-month intervals for a median follow-up time of 3.7 (interquartile range (IQR): 1.6; 6.3) years after initial imaging. During this period 196 patients (46.8%) had a primary outcome and 92 patients (22%) died. PM infarct was identified in 204 (48.7%) patients with twice as many posteromedial (PRM) (27%) than anterolateral (ARL) lesions (11%) and a similar number with infarct in both (11%). There was no association between studied outcomes and the presence of PMI in either PRM or ARL PM. The presence of infarct in both PM was a predictor of both the primary outcome (HR 1.69, CI[1.01-2.86], p<0.049.) and mortality (HR 1.69, CI[1.01-4.2], p<0.046). CONCLUSION The presence of infarct in either papillary muscle was not associated with outcomes. However, infarct involving both papillary muscles was associated with worse outcomes.