Abstract
BackgroundRoutine cine cardiovascular magnetic resonance (CMR) allows for the measurement of left atrial (LA) volumes. Normal reference values for LA volumes have been published based on a group of European individuals without known cardiovascular disease (CVD) but not on one of similar United States (US) based volunteers. Furthermore, the association between grades of LA dilatation by CMR and outcomes has not been established. We aimed to assess the relationship between grades of LA dilatation measured on CMR based on US volunteers without known CVD and all-cause mortality in a large, multicenter cohort of patients referred for a clinically indicated CMR scan.MethodWe identified 85 healthy US subjects to determine normal reference LA volumes using the biplane area-length method and indexed for body surface area (LAVi). Clinical CMR reports of patients with LA volume measures (n = 11,613) were obtained. Data analysis was performed on a cloud-based system for consecutive CMR exams performed at three geographically distinct US medical centers from August 2008 through August 2017. We identified 10,890 eligible cases. We categorized patients into 4 groups based on LAVi partitions derived from US normal reference values: Normal (21–52 ml/m2), Mild (52–62 ml/m2), Moderate (63–73 ml/m2) and Severe (> 73 ml/m2). Mortality data were ascertained for the patient group using electronic health records and social security death index. Cox proportional hazard risk models were used to derive hazard ratios for measuring association of LA enlargement and all-cause mortality.ResultsThe distribution of LAVi from healthy subjects without known CVD was 36.3 ± 7.8 mL/m2. In clinical patients, enlarged LA was associated with older age, atrial fibrillation, hypertension, heart failure, inpatient status and biventricular dilatation. The median follow-up duration was 48.9 (IQR 32.1–71.2) months. On univariate analyses, mild [Hazard Ratio (HR) 1.35 (95% Confidence Interval [CI] 1.11 to 1.65], moderate [HR 1.51 (95% CI 1.22 to 1.88)] and severe LA enlargement [HR 2.14 (95% CI 1.81 to 2.53)] were significant predictors of death. After adjustment for significant covariates, moderate [HR 1.45 (95% CI 1.1 to 1.89)] and severe LA enlargement [HR 1.64 (95% CI 1.29 to 2.08)] remained independent predictors of death.ConclusionLAVi determined on routine cine-CMR is independently associated with all-cause mortality in patients undergoing a clinically indicated CMR.
Highlights
Routine cine cardiovascular magnetic resonance (CMR) allows for the measurement of left atrial (LA) volumes
We aimed to measure the association of all-cause mortality with different severity grades LA enlargement, derived from using routine clinically available CMR images using the area-length method in a large patient population referred for CMR
Inter-site reproducibility was excellent between the central reader and the three different sites (Overall [n = 90] Intraclass correlation coefficients (ICC): 0.94 [95% confidence interval (CI) 0.91, 0.96] and Bias: 1.84 [95% limits of agreement (LOA) 16.45, − 12.8], Site 1 [n = 30] ICC: 0.95 [95% CI 0.9, 0.98] and Bias: 2.6 [95% LOA 16.8, − 11.6], Site 2 [n = 30] ICC: 0.94 [95% CI 0.78, 0.98] and Bias: 5.2 [95% LOA 19.2, − 8.8], and Site 3 [n = 30] ICC: 0.92 [95% CI 0.83, 0.96] and Bias: -2.3 [95% LOA 9.6, − 14.1])
Summary
Routine cine cardiovascular magnetic resonance (CMR) allows for the measurement of left atrial (LA) volumes. We aimed to assess the relationship between grades of LA dilatation measured on CMR based on US volunteers without known CVD and all-cause mortality in a large, multicenter cohort of patients referred for a clinically indicated CMR scan. Reference LA chamber size values have been defined from multiple studies, the process requires tomographic slices through the atrial chambers that is not routinely used in clinical practice, as it can be time-consuming and challenging for clinical patients with dyspnea These reference values are based off of studies using European subjects and there have been no known studies comprising healthy subjects without known cardiovascular diseases (CVD) from the United States that may vary in body habitus and ethnicity. We aimed to measure the association of all-cause mortality with different severity grades LA enlargement, derived from using routine clinically available CMR images using the area-length method in a large patient population referred for CMR
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
