Early positive electrical remodeling after mavacamten therapy in obstructive hypertrophic cardiomyopathy
M E Koilakou, A Kasiakogias, F E Kourti, V Gardikioti, A Kourountzoglou, T Tsampras, A Xintarakou, D Kyriakopoulos, C Kaskoutis, A S Antonopoulos, D Terentes-Printzios, A Miliou, G Lazaros, K Tsioufis, C VlachopoulosAbstract
Background/Introduction
The electrocardiogram (ECG) in obstructive hypertrophic cardiomyopathy (oHCM) frequently presents with T-wave inversions (TWI) and positive voltage criteria for left ventricular hypertrophy (LVH). Mavacamten, a selective cardiac myosin inhibitor, improves hemodynamics and induces structural reverse remodeling; however, its effects on ECG parameters remain incompletely characterized.
Purpose
To evaluate the impact of mavacamten therapy on ECG markers of repolarization abnormalities and LVH in patients with oHCM.
Methods
We prospectively evaluated 33 consecutive patients (mean age 62.8 ± 10.9 years old, 38% male) with oHCM treated with mavacamten. Standard 12-lead ECGs were obtained at baseline and after 12 weeks of therapy, with additional 24-week follow-up available in a subset. ECGs were analyzed for heart rhythm, ECG intervals, and the presence, distribution, depth and extent of TWI excluding leads V1, aVR, and III. TWI was further reviewed by location as negative T-waves ≥1 mm in ≥2 contiguous leads. LVH was assessed using Sokolow–Lyon and Cornell voltage criteria. Patients with paced rhythm or bundle branch block were excluded (N=8).
Results
Among 25 patients with paired baseline and 12-week ECGs 5 patients (20%) had no TWI, 12 (48%) exhibited TWI in 1–4 leads, and 8 (32%) had extensive TWI (≥5 leads). At 12 weeks, patients without TWI increased to 40% (n=10), while those with TWI in 1–4 and ≥5 leads decreased to 36% (n=9) and 24% (n=6), respectively. The number of patients with lateral TWI reduced from n=17 (68%) at baseline to n= 9 patients (35%) at 12 weeks; concomitant decreases were observed in the number of patients with inferior (n=4 to n=2), inferolateral (n=4 to n=1), anterior (n=3 to n=2), and anterolateral leads (n=3 to n=2). The depth of TWI decreased from baseline to week 12 by an average of 0.46 mm in lead I and 0.50 mm in lead aVL (p = 0.021 and p = 0.018, respectively). In patients with available 24-week follow-up (n=16), further improvements were observed, with absence of TWI increasing from 31% at baseline to 63% at 24 weeks and presence of extensive TWI decreasing from 31% to 6% of patients. ECG voltage criteria for LVH also declined; at 12 weeks, Sokolow–Lyon positivity decreased from 44% to 24% of patients, whereas Cornell criteria showed a modest reduction (56% to 52%). At 24 weeks, Sokolow–Lyon positivity decreased from 38% to 13% and Cornell positivity from 50% to 19% of patients.
Conclusions
After 12 weeks of mavacamten treatment, patients showed significant rates of reversal in T-wave inversion, predominantly observed in the lateral leads, along with a reduction in the prevalence of Sokolow–Lyon voltage criteria for LVH. These findings indicate early electrocardiographic changes consistent with electrical remodeling during mavacamten treatment.