Background: Percutaneous transluminal septal myocardial ablation (PTSMA) reduces left ventricular outflow (LVOT) gradient in patients with hypertrophic obstructive cardiomyopathy (HOCM) and leads to symptomatic improvement. Effects of PTSMA on left ventricular performance are currently unknown. The purpose of this study was to evaluate changes in the left ventricular performance using Doppler index of myocardial performance (sum of isovolumic contractile and relaxation times divided by left ventricular ejection time) and left ventricular remodelling after PTSMA for HOCM.
Methods: Twenty-five patients with symptomatic HOCM underwent echocardiography-guided PTSMA procedure. Clinical and echocardiographic data were collected at baseline and 3 months after PTSMA.
Results: PTSMA procedures were uneventful, in one patient (4%), pacemaker implantation was needed for sustained complete heart block after the procedure. At 3-month follow-up, the maximal LVOT gradient decreased from 68+/-39 to 18.6+/-12 mmHg (P<0.001), the provoked maximal LVOT gradient decreased from 128.8+/-59 to 25+/-21.4 mmHg (P<0.001), and basal septal thickness decreased from 21.7+/-4 to 15.2+/-3 mm (P<0.001). The improvement of the index of myocardial performance (from 0.65+/-7 to 0.56+/-11; P<0.001) was associated with neither significant change in left ventricular ejection fraction nor left ventricular ejection time. There was no significant difference in the left ventricular dimension at baseline and at follow-up. All patients reported a significant improvement in symptoms at follow-up, the mean NYHA class decreased from 2.6+/-0.7 to 1.4+/-0.7 (P<0.001), and the number of patients suffering from episodes of syncope or attacks of dizziness decreased from 13 to two during the 3-month follow-up.
Conclusions: PTSMA is a safe, effective and reproducible method in the treatment of highly symptomatic patients with HOCM. This procedure results in a significant relief of symptoms associated with decrease in LVOT gradient and thickness of basal interventricular septum. Positive changes in Doppler IMP suggest possible improvement of left ventricular function.