During a mean follow-up of 10.72 ± 11.02(1–24) months, there were no instances of lethal arrhythmia, myocardial infarction, stroke or death. Until the latest follow-up, all the patients had a significant reduction in limiting symptoms (e.g. shortness of breath) and a significant increase in physical capacity. The mean NYHA functional class decreased from 3.09 ± 0.60 (2–4) preoperatively to 1.12 ± 0.32 at the time of latest follow-up (P < 0.0005). Eighty-two patients (NYHA class α, β or χ preoperatively) were free of limiting symptoms (NYHA class I) at the latest follow-up, and 11 (NYHA class β or χ preoperatively) had very mild limitations (NYHA class II). TTE identified that the LVOT turned to be widely patent throughout the cardiac cycle. Significant reductions to a mean level of 14.78 ± 14.01 mmHg were recorded by continuous-wave Doppler in peak instantaneous LVOT gradient. Mitral regurgitation remained absent (51) or at mild-(41)-to-moderate (1) levels. The main echocardiographic and NYHA data are shown in Table 2.
Table 2: Parameters measured pre- and postoperatively, expressed as mean value (range) or number (%)
Parameter Preoperatively Postoperatively P-value
LVOT peak gradient (mmHg) 91.76 ± 25.08 14.78 ± 14.01 <0.0005
Mean MR level 1.35 ± 0.97 0.46 ± 0.52 <0.0005
 None (0/4) 20 51
 Mild (1/4) 32 41
 Moderate (2/4) 30 1
 Moderately severe (3/4) 10 0
 Severe (4/4) 1 0
SAM (n, %) 93 (100%) 1 (1.1%) <0.0005
NYHA class 3.09 ± 0.60 1.12 ± 0.32 <0.0005
 I (1/4) 0 81
 II (2/4) 13 12
 III (3/4) 59 0
 IV (4/4) 21 0
Mean mitral regurgitation (MR) levels are scored as 0–4, to define no (0), mild (1), moderate (2), moderately severe (3) or severe regurgitation (4). NYHA class are scored as 1–4, to define classes I–V, respectively.