Left Atrial Size and Function in Hypertrophic Cardiomyopathy Patients and Risk of New-Onset Atrial Fibrillation

Abstract

Background— The value of left atrial (LA) diameter, volume, and strain to risk stratify hypertrophic cardiomyopathy patients for new-onset atrial fibrillation (AF) was explored. Methods and Results— A total of 242 hypertrophic cardiomyopathy patients without AF history were evaluated by (speckle-tracking) echocardiography. During mean follow-up of 4.8±3.7 years, 41 patients (17%) developed new-onset AF. Multivariable analysis showed LA volume (≥37 mL/m 2 ; hazard ratio, 2.68; 95% confidence interval, 1.30–5.54; P =0.008) and LA strain (≤23.4%; hazard ratio, 3.22; 95% confidence interval, 1.50–6.88; P =0.003), but not LA diameter (≥45 mm; hazard ratio, 1.67; 95% confidence interval, 0.84–3.32; P =0.145), as independent AF correlates. Importantly, 59% (n=24) of AF events occurred despite a baseline LA diameter <45 mm, observed in 185 patients. In this patient subset, LA strain (area under the curve 0.73) and LA volume (area under the curve 0.83) showed good predictive value for new-onset AF. Furthermore, patients with LA volume <37 versus ≥37 mL/m 2 and LA strain >23.4% versus ≤23.4% had superior 5-year AF-free survival of 93% versus 80% ( P =0.003) and 98% versus 74% ( P =0.002), respectively. Importantly, LA volume <37 mL/m 2 and strain >23.4% yielded high negative predictive value (93% and 98%, respectively) for new-onset AF. Likelihood ratio test indicated incremental value of LA volume assessment ( P =0.011) on top of LA diameter to predict new-onset AF in hypertrophic cardiomyopathy patients with LA diameter <45 mm, which tended to increase further by addition of LA strain ( P =0.126). Conclusions— LA diameter, volume, and strain all relate to new-onset AF in hypertrophic cardiomyopathy patients. In patients with normal LA size, however, both LA volume and strain further refine risk stratification for new-onset AF.

In-Hospital Postoperative Atrial Fibrillation Indicates a Poorer Clinical Outcome after Myectomy for Obstructive Hypertrophic Cardiomyopathy

“…22) In patients with a normal LA size, LAV can refine risk stratification for new-onset AF. 23) In accordance with a previous report, 22,24) elevated LAV was independent indicators of POAF. LAV may own more pathophysiological significance and prognostic value than LAD because LAV can reflect the enlargement of LA more accurately in consideration of the stereochemical structure.…”

Echocardiographic advances in hypertrophic cardiomyopathy: Three‐dimensional and strain imaging echocardiography

“…Even if the prognostic role of STE in these conditions is still not widely validated, myocardial strain analysis is a feasible tool to identify and follow-up subtle change not clearly observed with standard echocardiography. Similarly, the strong predictive value of LA volume and LA strain for new-onset AF was recently observed (area under curve 0.83 and 0.73, respectively) in affected patients 58 (Figure 3).…”

“…Similarly, the strong predictive value of LA volume and LA strain for new‐onset AF was recently observed (area under curve 0.83 and 0.73, respectively) in affected patients (Figure ).…”

Hypertrophic Cardiomyopathy

“…205, 208, 209 It is also a major risk factor for thromboembolic stroke. 205, 207, 208 Left atrial size and function as well as LVOT obstruction are major risk factor for atrial fibrillation 207 . The underpinning mechanism(s) of atrial fibrillation in HCM has not been delineated.…”