Assessment of Cardiac Calcifications on Echocardiography Are Associated With Mortality and Stroke
Lu ML, Gupta S, Romero-Corral A, et al. J Am Soc Echocardiogr. 2016;29(12):1171–1178.
Reviewers: Elizabeth Ungerman, MD1; Kathirvel Subramaniam, MD MPH1
- University of Pittsburgh Medical Center, Pittsburgh, PA
Routine echocardiography often reveals the unexpected—or sometimes more than expected. The presence of calcifications often correlate with underlying pathology or comorbid conditions. Current routine echocardiographic evaluation does not involve the use of a quantitative scoring system for assessment of intracardiac calcifications. This retrospective study implemented the use of Global Cardiac Calcium Score (GCCS) to stratify the risk of all-cause mortality and stroke in patients who had echocardiograms during the specific time period.
The study was conducted utilizing patients receiving transthoracic echocardiography (TTE) from January 1, 2007, to January 31, 2011, at Albert Einstein Healthcare Network in Philadelphia, PA. GCCS includes location of calcification, its thickness, and subsequent limitation of motion of the valve. Aortic valve, aortic annulus, aortic root, mitral valve, mitral annulus, and subvalvular apparatus were evaluated for calcification. The relationship between GCCS and mortality/stroke was evaluated after adjusting for relevant variables (age, hypertension, dyslipidemia, diabetes, cancer, chronic kidney disease, smoking, and right ventricle function) and interpreter bias. They divided patients into tertiles (GCCS <3, 3–4, and > 4) and evaluated the adjusted proportional hazard ratios (HR) for stroke and all-cause mortality.
A total of 443 patients were included in the study, and they underwent TTE for any clinical indication that did not meet exclusion criteria set forth by the investigators. The average age was 57 +/- 18 years with 48% and 65% of the population being males and African Americans, respectively. The mean time for follow-up from the study was 3.8 +/- 1.7 years. The vast majority (87%) of subjects were found to have a GCCS ≥1, with a mean of 3.3 +/- 2.2. Overall mortality was 116 (26%) and there were 34 nonfatal strokes. After adjusting for potential confounders and intra- and inter-observer variability, an increasing GCCS was significantly associated with overall mortality (HR 1.24, 95% confidence interval [CI], 1.17–1.34) and stroke (HR 1.25, 95% CI 1.07–1.44). Hypertension and hyperlipidemia were independently associated with overall mortality. Increasing age and diabetes were independently associated with increasing stroke. Calcific lesion location also was significantly associated with mortality but not with stroke.
Although there is no formal system for evaluating patients who may be at a greater risk for all-cause mortality and stroke morbidity with TTE, this article brings to light the appreciation of identifying high-risk patients for these adverse outcomes. It is well known that calcifications correlate with underlying vascular inflammation and remodeling. The study shows significant correlations and associations between calcifications and the selected adverse outcomes. The authors recognize their own limitations and weaknesses, and attempt to adjust for variability when able. First, the cause of death was not evaluated. Incidence of complications was very high and the majority of patients belonged to the African-American community.
Although the concept of this retrospective cohort study was developed in hopes to identify high-risk patients, there is no indication of how this scoring system will alter medical management of these patients. Most of the patients that were excluded in this study had a medical history of cardiac disease or renal disease that could possibly act as confounding variables; however, an important subset of patients that need consideration are patients that were undergoing TTE as part of a syncopal workup or had a history of previous stroke or transient ischemic attack. Lastly, TTE may not be able to differentiate between sclerotic thickening and calcifications.