Background: Transcoronary septal ablation is efficacious for patients with symptomatic hypertrophic obstructive cardiomyopathy (HOCM) and outflow-tract gradient (OTG). However, while patients with symptomatic concentric left ventricular hypertrophy (CLVH) may develop OTG, the safety and efficacy of septal ablation in these patients is unknown.
Objectives: To determine the potential safety and efficacy of transcoronary alcohol septal ablation in refractory, symptomatic patients with CLVH and significant OTG.
Methods: We identified 9 patients (all female; age, 67.6 ± 8.7 years) with CLVH and OTG who underwent septal ablation on a compassionate basis and for symptomatic relief, with CLVH defined as left ventricular wall thickness > 15 mm in the absence of asymmetric septal hypertrophy. CLVH patients were compared with age-, sex- and OTGmatched HOCM patients (resting OTG, 56.7 ± 22.4 versus 58.3 ± 33.5 mmHg, respectively; p = 0.91).
Results: In CLVH patients, mean resting OTG decreased to 22.8 ± 12.5 mmHg (p < 0.0005 versus baseline), which was comparable to the change in HOCM patients (p = 0.45 CLVH versus HOCM). Peak inducible OTG in CLVH patients also decreased following septal ablation (142.2 ± 36.3 to 36.1 ± 16.2 mmHg; p < 0.0001). Baseline left ventricular end-diastolic pressure (LVEDP) was similar between CLVH (17.7 ± 3.7 mmHg) versus HOCM (16.3 ± 4.0 mmHg; p = 0.50). Following ablation, LVEDP decreased by 3.4 ± 1.9 mmHg in CLVH (p < 0.001 versus baseline) and 3.0 ± 2.2 mmHg in HOCM patients (p = 0.67 CLVH versus HOCM). Complication rates were similar between groups. Baseline New York Heart Association class was 3.6 ± 0.5 for CLVH versus 3.3 ± 0.5 for HOCM (p = 0.51). Both groups experienced symptomatic improvement following ablation (p < 0.0005), and at long-term follow up (34.9 ± 23.9 months), these changes were similar and sustained.
Conclusion: Septal ablation holds promise for the management of symptomatic CLVH with OTG.