Dataset Information

Prevention of sudden cardiac death in hypertrophic cardiomyopathy: Risk assessment using left atrial diameter predicted from left atrial volume.

ABSTRACT:

Background

Left atrial diameter (LAd) is included in the European Society for Cardiology's (ESC) risk model for assessment of sudden cardiac death (SCD) risk in hypertrophic cardiomyopathy (HCM), but the recommended measure of LA size is left atrial volume (LAv).

Hypothesis

We hypothesized that LAv could be used instead of LAd in the HCM risk-SCD model. We aimed to determine the relation between LAd and LAv and to assess the impact of using LAv instead of LAd.

Methods

Echocardiographic measurements of anteroposterior LAd in the parasternal long-axis window and LAv from Simpson's biplane method of disks were used. The 5-year risk of SCD by measured LAd and by LAd predicted from LAv were estimated using the ESC risk-SCD model.

Results

In 205 HCM patients (age 56 ± 14 years, 62% male), the relation between LAd and LAv was linear. Median 5-year risk of SCD was 2.4% (interquartile range [IQR]: 1.6; 3.8) using measured LAd and 2.4% (IQR: 1.6; 3.7) using predicted LAd. The correlation between the SCD risk assessed by measured vs predicted LAd was excellent (r² = 0.96). Use of predicted LAd resulted in four patients (2%) being recategorized between the moderate and high-risk categories.

Conclusions

The relation between LAd and LAv was linear with good agreement. On a population level, the correlation between the risk of SCD using measured LAd or LAd predicted from LAv was excellent. On a patient level, using LAd predicted from LAv resulted in the vast majority remaining in the same risk category; however, for a minority of patients, it changed the recommendation.

SUBMITTER: Mills H

PROVIDER: S-EPMC7298985 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundMaximal left ventricular wall thickness (MLVWT) is a risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). In adults, the severity of left ventricular hypertrophy has a nonlinear relationship with SCD, but it is not known whether the same complex relationship is seen in childhood. The aim of this study was to describe the relationship between left ventricular hypertrophy and SCD risk in a large international pediatric HCM cohort.MethodsThe study cohort comprised 1075 children (mean age, 10.2 years [±4.4]) diagnosed with HCM (1-16 years) from the International Paediatric Hypertrophic Cardiomyopathy Consortium. Anonymized, noninvasive clinical data were collected from baseline evaluation and follow-up, and 5-year estimated SCD risk was calculated (HCM Risk-Kids).ResultsMLVWT Z score was <10 in 598 (58.1%), ≥10 to <20 in 334 (31.1%), and ≥20 in 143 (13.3%). Higher MLVWT Z scores were associated with heart failure symptoms, unexplained syncope, left ventricular outflow tract obstruction, left atrial dilatation, and nonsustained ventricular tachycardia. One hundred twenty-two patients (71.3%) with MLVWT Z score ≥20 had coexisting risk factors for SCD. Over a median follow-up of 4.9 years (interquartile range, 2.3-9.3), 115 (10.7%) had an SCD event. Freedom from SCD event at 5 years for those with MLVWT Z scores <10, ≥10 to <20, and ≥20 was 95.6%, 87.4%, and 86.0, respectively. The estimated SCD risk at 5 years had a nonlinear, inverted U-shaped relationship with MLVWT Z score, peaking at Z score +23. The presence of coexisting risk factors had a summative effect on risk.ConclusionsIn children with HCM, an inverted U-shaped relationship exists between left ventricular hypertrophy and estimated SCD risk. The presence of additional risk factors has a summative effect on risk. While MLVWT is important for risk stratification, it should not be used either as a binary variable or in isolation to guide implantable cardioverter defibrillator implantation decisions in children with HCM.

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