High altitudes, deeper insights: multicenter cardiovascular magnetic resonance study on hypertrophic cardiomyopathy

Objectives: Altitude is a known factor in cardiovascular disease, but its impact on hypertrophic cardiomyopathy (HCM) patients remains unclear. This study aimed to determine whether living at high altitudes affects the extent of late gadolinium enhancement (LGE) and left ventricular (LV) strain in HCM patients.

Methods: This retrospective cross-sectional study was conducted across four hospitals located at different altitudes in China. A total of 256 HCM patients who underwent cardiac magnetic resonance (CMR) imaging between May 2019 and November 2021 were included. Patients were categorized into two groups: the high-altitude group (median interquartile range [IQR]: 1520.00 [1520.00, 1917.00] meters, n = 132) and the low-altitude group (86.45 [43.50, 150.75] meters, n = 124). The extent of LGE and global LV strain were assessed and compared between these groups.

Results: The median age of the study population was 55 years (IQR: 46-63), with 59% of participants being male. The high-altitude group exhibited a significantly greater extent of LGE compared to the low-altitude group (median [IQR]: 8.10 [4.78, 19.98]% vs. 6.20 [1.89, 13.81]%; p = 0.008). Multivariable analysis identified altitude as an independent predictor of increased LGE extent (β = 4.41; 95% CI: 2.04 to 6.78; p < 0.001). Additionally, altitude was positively associated with LV strain in the longitudinal, circumferential, and radial directions (all p < 0.050).

Conclusion: HCM patients living at higher altitudes exhibit a significant increase in LGE extent and more favorable LV strain parameters.

Key points: Question Does altitude affect the extent of late gadolinium enhancement (LGE) and left ventricular strain in patients with hypertrophic cardiomyopathy (HCM)? Findings High altitude is associated with a significantly greater extent of LGE and less impairment in global longitudinal strain in HCM patients. Clinical relevance HCM patients living at higher altitudes exhibit a significant increase in LGE extent and the mismatch of left ventricular strains. Doctors should consider these findings to tailor treatment and follow-up plans for HCM patients living in high altitudes.