Global and Temporal Trends in Utilization and Outcomes of Implantable Cardioverter Defibrillators in Hypertrophic Cardiomyopathy

Abstract

Background: Over the past decades, hypertrophic cardiomyopathy has become a contemporary treatable disease. However, limited data exist on the global trends of implantable cardioverter defibrillator (ICD) utilization and its impact on mortality/morbidity burden reduction.

Methods: Electronic databases were systematically searched up to March 2024 for studies reporting on ICD utilization rates in hypertrophic cardiomyopathy. A random effects model was used to pool study estimates across time-era, geographic region, and age group. Primary outcome was global trends in ICD utilization. Secondary outcomes included trends of sudden cardiac death, appropriate/inappropriate shocks, and ICD-related complications.

Results: In total, 234 studies (N=92 500, 514 748 patient-years) met inclusion criteria. Mean age was 46.2 (12.4) years and 37.49% were women. A total of 12 139 patients (16.43%) received an ICD over 429 766 person-years of follow-up, with an ICD implantation rate of 2.79%/y ([95% CI, 2.35%-3.32%] I²=97.80%). Rates of ICD implantation steadily increased over time from 1990 (1.09%) to 2021 (4.01%; P=0.002), with noticeable geographic variation (P=0.008). The overall rate of appropriate ICD discharges and ICD-related complications was 3.44%/y ([95% CI, 3.08%-3.84%] I²=88.40%) and 1.98%/y ([95% CI, 1.52%-2.59%] I²=90.44%), respectively, with no significant trend over time. The overall rate of inappropriate discharges was 3.58%/y ([95% CI, 3.08%-4.16%] I²=88.03%), and declined significantly over time (P=0.044). There was a significant decline in the rates of sudden cardiac death from 1990 (0.84%/y) to 2020 (0.31%/y).

Conclusions: Dramatic increases in ICD utilization have occurred, representing a 3.7-fold increase, with appropriate therapies occurring in 3.44%/y. In parallel a significant reduction in sudden cardiac death was observed, but there are insufficient data to demonstrate that a causative relationship exists. Geographic disparities in ICD utilization were evident, highlighting the need to improve access to specialized care for patients with hypertrophic cardiomyopathy. Geographic disparities in ICD utilization were evident, highlighting the need to improve access to specialized care for patients with hypertrophic cardiomyopathy.

Registration: URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42023407126.

Keywords: cardiomyopathy, hypertrophic; death, sudden, cardiac; defibrillators, implantable; morbidity; mortality.

Figure 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram for study selection.

Figure 2.

Temporal trends of implantable cardioverter defibrillator (ICD) utilization in hypertrophic cardiomyopathy between 1990 and 2021.

Figure 3.

Global Trends in implantable cardioverter defibrillator (ICD) implantation rates. Geographic trends in ICD implantation rates: (A) geographic variations in annual trends of ICD implantation; (B) ICD implantation stratified by geography pre- and post-2010.

Figure 4.

Implantable cardioverter defibrillator (ICD) implantation stratified by age groups.

Figure 5.

Global Trends of implantable cardioverter defibrillator (ICD) Appropriate Therapy. Temporal trends of appropriate ICD therapy: (A) ICD shocks; (B) antitachycardia pacing.

Figure 6.

Temporal trends of inappropriate implantable cardioverter defibrillator (ICD) shocks.

Figure 7.

Global Trends of implantable cardioverter defibrillator (ICD) complications. Temporal trends of ICD–related complication rates: (A) geographic variations in annual trends of ICD-related complications; and (B) worldwide trends of ICD complications.

Figure 8.

Global Trends of Mortality and sudden cardiac death. Temporal trends of mortality in hypertrophic cardiomyopathy: (A) sudden cardiac death; (B) all-cause mortality.