Obstructive – Nonobstructive hypertrophic cardiomyopathy: differences and predictors

Abstract

Introduction

Hypertrophic cardiomyopathy(HCM) is a genetic cardiomyopathy with a prevalence of 1/500 and causes adverse outcomes, usually due to left ventricular outflow tract obstruction.

Aim

In this study, we aimed to determine the possible differences and predictors of obstructive hypertrophic cardiomyopathy HCM (Obs-HCM) and nonobstructive HCM (Nonobs-HCM) by electrocardiographic (ECG) and echocardiographic (ECHO) evaluations with clinical, demographic, and biochemical characteristics.

Methods

This study is a subgroup analysis of a multicentre, national, and observational 'LVH-TR study’ that included 886 left ventricular hypertrophy(LVH) patients in 22 centres between February 2020 and August 2021. After excluding six patients with atrial fibrillation, pace rhythm, bundle branch blocks, and second, and third-degree atrioventricular(AV) block, 60 HCM patients were included, 23 of whom were obstructive, and 37 were nonobstructive.

Results

Body surface area(BSA) (2.01 ± 0.17, 1.89 ± 0.19; p = .01), ST-segment depression (%82.6, %54.1; p = .02), QT and QTc durations (436.3 ± 58.3, 398.0 ± 65.5; p = .02/470.6 ± 58.7, 432.8 ± 74.7; p = .04), left ventricular mass index(LVMI) (176.4 ± 47.0, 152.7 ± 10.2; p = .004), and systolic anterior motion(SAM) rates (%82.6, %18.9; p < 0.001) were significantly higher in the obstructive HCM compared to nonobstructive HCM. Furthermore, the significance of ST-segment depression, QT duration, LVMI, and SAM continued in the univariate analyses to assess obstruction prediction (all p values < .05).

Conclusion

In multivariate and correlation analyses, ST segment depression (rho = 0.29), QT prolongation (rho = 0.34), and SAM (rho = 0.62) are found as predictors for obstruction (all p values < .05). Our study will guide future studies since it has detailed ECG and ECHO comparisons of Obs-HCM and Nonobs-HCM patients over 18 are made.

Keywords:

• Left ventricular hypertrophy
• cardiomyopathy
• echocardiography
• cardiovascular imaging

Acknowledgments

The LVH-TR study collaborates; Selvi Oztas, Ahmet Oz, Gulay Gok, Zeynep Kolak, Ercan Aksit, Suleyman Anıl Sarica, Murat Bayrak, Berkay Ekici, Oguzhan Birdal, Berat Uguz, Mesut Gitmez, Fatma Nihan Turhan Caglar, Gul Ilayda Berk, Mustafa Oguz, Ali Nazmi Calik, Salih Kilic, Yasemin Dogan, Abdullah Yildirim, Lutfu Bekar, Hazar Harbalıoğlu, Dilay Karabulut, Elton Soydan and Oktay Ergene. We thank them for their contributions to the preparation of this manuscript.

Authors contribution

Conceptualisation: OA, MK, TG, Data collection, and analysis: OA, MK, TG, MD, MZ, Investigation: OA, MK, TG, MD, MZ, Methodology: OA, MK, TG, MZ, Reviewing-editing: OA, MK, TG, MD, MZ, Writing: OA, MK, TG, MD, MZ

Ethical approval

Our study was carried out following ethical standards under the Helsinki Declaration. Accordingly, the Bakırkoy Dr. Sadi Konuk Training and Research Hospital Clinical Research ethics committee approved our study with the date 20.01.2020 and the number 2020-02-21.

Local ethical approval received.

Informed consent forms were obtained from all patients.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

All authors declare that the study has no funding and conflict of interest.