Alternative Methods
Dual chamber pacing (DDD) may be able to relieve symptoms in those
patients who are deemed high risk for ASA. Krejci et al. compared the
long-term effects of DDD pacing and ASA in symptomatic patients.
Patients treated with DDD pacing had reduced NYHA class symptoms, and
LVOT gradient, however no significant difference in change in LVOT
gradient and left ventricular ejection fraction (LVEF) was found between
both groups. The ASA group showed greater improvement in NYHA class,
greater reduction in interventricular septum (IVS) thickness and LV
diastolic diameter. Both groups were followed up over a period of 7-8
years and revealed that ASA can provide a consistent reduction in LVOT
gradient over this period. Surgical myectomy or ASA can effectively
reduce the physical obstruction in HOCM by reducing basal septal
hypertrophy and relieve SAM, and are the ideal methods for symptomatic
patients, DDD appears to produce promising results in the long term
reduction of LVOT gradients and may be useful in high risk patients,
this however will require further study. [19]
Surgical myectomy (SM) has been deemed to be gold standard in the
invasive treatment of HOCM, and a preferable option to younger and low
risk patients (table 3). Surgical myectomy is also a convenient option
to those who need concomitant cardiac surgery such as coronary artery
bypass grafting or surgical valve replacement. Good results have been
shown in high volume centres. Rastegar et al. performed surgical
myectomy on patients with NYHA class III-IV symptoms; they found
significant reduction in resting LVOT gradients. Of the 31 patients who
had severe MR, 87% had no or mild MR post procedure. 30-day deaths were
0.8% and no patient required repeat intervention, and 3% had ASA prior
to SM and required reintervention due to heart failure symptoms. 43 out
of 482 patients needed PPM, 4 developed ischaemic stroke in the peri
operative period and 21% developed atrial fibrillation. At follow up
64% had NYHA class I and 29% with class II symptoms. [20] Xin et
al. evaluated the follow up results of those who underwent ASA and SM.
No significant differences were noted in IVS thickness reduction, LV end
diastolic diameter, or degree of SAM at follow up between the two
groups. There was however greater reduction in the resting LVOT gradient
in the SM group, with 81% of patients having completely eliminated
their pressure gradients. Both groups showed improvement with NYHA
class, but there was no significant difference. PPM implantation was
24% and 7.7% in the ASA and SM groups respectively and hospital stay
was much shorter in the ASA group. [21] Yao et al. also produced
promising results with SM, showing no deaths within 30 days,
post-operative hospital stay was around 10 +/- 5, and NYHA reduced
greatly from 2.5- and 5-years post-surgery. Severe and moderate MR had
completely disappeared and the most common post-operative arrhythmia was
left bundle branch block (LBBB) 24.5%. [22]
Firoozi et al. performed a non-randomised cohort study comparing ASA and
SM. They found that both procedures had significant reduction in LVOT
gradients; with 91% of SM patients having a gradient below 20 mmHg post
procedure, compared to the 74% in the ASA group. 15% of the ASA group
required PPM compares to the 4% in the SM group. The improvement in
functional class was similar in both groups. Peak VO2 was greater in the
myectomy group. Peak LVOT gradient at 12 months were similar in both
groups. [23]