Presence of Apical Aneurysm and Its Impact on Left Ventricular Mechanics and Mechano-Energetic Coupling in Patients With Apical Hypertrophic Cardiomyopathy

Abstract

Background

Left ventricular (LV) apical aneurysms (ApAn+) occur in 10%–15% of apical hypertrophic cardiomyopathy (ApHCM) patients and confer considerable morbidity. We hypothesized that ApAn+ adversely impact ventricular mechanics and mechano-energetic coupling in ApHCM.

Methods

Ninety-eight ApHCM patients were identified, of which nine (9%) had ApAn+ and were compared with 89 (91%) who did not (ApAn−). 2D speckle-tracking echocardiography assessed ventricular mechanics using LV global longitudinal strain (GLS) and torsion, and mechano-energetic coupling as myocardial work indices. Clinical events over follow-up were adjudicated.

Results

Mean age was 64 ± 15 years, 46% were female, and 3% had an HCM family history, with similar clinical risk factors between groups. Of the nine ApAn+ patients, there were six small (<2 cm) and three moderate-sized (2-4 cm) aneurysms. There was no difference in LV ejection fraction (65 ± 15 vs. 67 ± 11%, p = 0.51) or GLS (−9.6 ± 3.3 vs. −11.9 ± 3.9%, p = 0.09) between ApAn+ versus ApAn−. ApAn+ patients had greater myocardial global wasted work (347 ± 112 vs. 221 ± 165 mmHg%, p = 0.03) and lower global work efficiency (GWE, 75 ± 5 vs. 82 ± 8%, p = 0.006). LV GLS (β = −0.67, p < 0.001), ApAn+ (β = −0.15, p = 0.04), and twist rate (β = −0.14, p = 0.04) were independently associated with GWE. At 3.9-year follow-up, cardiovascular mortality (4%) and heart failure hospitalization (14%) events were similar between groups.

Conclusion

ApHCM patients with ApAn+ are characterized by more impaired LV mechano-energetic coupling when compared with ApAn−. ApAn+ is independently associated with worse GWE.