Pattern and degree of left ventricular remodeling following a tailored surgical approach for hypertrophic obstructive cardiomyopathy

Abstract

Background The role of a tailored surgical approach for hypertrophic cardiomyopathy (HCM) on regional ventricular remodelling remains unknown. The aims of this study were to evaluate the pattern, extent and functional impact of regional ventricular remodelling after a tailored surgical approach. Methods From 2005 to 2008, 44 patients with obstructive HCM underwent tailored surgical intervention. Of those, 14 were ineligible for cardiac magnetic resonance (CMR) studies. From the remainder, 14 unselected patients (42±12 years) underwent pre- and post-operative CMR studies at a median 12 months post-operatively (range 4–37 months). Regional changes in left ventricular (LV) thickness as well as global LV function following surgery were assessed using CMR Tools (London, UK). Results Pre-operative mean echocardiographic septal thickness was 21±4 mm and mean LV outflow gradient was 69±32 mmHg. Following surgery, there was a significant degree of regional regression of LV thickness in all segments of the LV, ranging from 16% in the antero-lateral midventricular segment to 41% in the anterior basal segment. Wall thickening was significantly increased in basal segments but showed no significant change in the midventricular or apical segments. Globally, mean indexed LV mass decreased significantly after surgery (120±29nbspnormalg/m2 versus 154±36nbspnormalg/m2; p<0.001). There was a trend for increased indexed LV end-diastolic volume (70±13 mL versus 65±11 mL; p=0.16) with a normalization of LV ejection fraction (68±7% versus 75±9%; p<0.01). Conclusion Following a tailored surgical relief of outflow obstruction for HCM, there is a marked regional reverse LV remodelling. These changes could have a significant impact on overall ventricular dynamics and function.

Impact of Demographic Features, Lifestyle, and Comorbidities on the Clinical Expression of Hypertrophic Cardiomyopathy

“…Of note, reduction of LV mass following resolution of afterload mismatch occurred in regions of HCM hearts remote from the septum, suggesting that reverse remodeling may occur in this disease on removal of pathologic environmental stimuli. 60,61 This general concept of partial reversibility of LVH in patients with HCM requires further investigation and is of relevance to other potential determinants such as sport, obesity, and renal failure.…”

INHERIT (INHibition of the renin angiotensin system in hypertrophic cardiomyopathy and the Effect on hypertrophy—a Randomised Intervention Trial with losartan)

“…Indeed, while the aforementioned MRI studies following invasive septal reduction therapies have shown significant reduction of hypertrophy in similar time frames, they have likely benefitted from the acute effect exerted by the relief of obstruction in rapidly reversing a quota of “secondary” LVH. 14 , 15 Such advantage could not be exploited in the INHERIT, and it is possible that longer observation times may be required to observed a comparable effect by pharmacological interventions in HCM hearts. The data on myocardial fibrosis, however, suggests that larger and longer studies are unlikely to show different results in this disease.…”

“…Indeed, cardiac magnetic resonance imaging (MRI) studies have demonstrated that the degree of LVH can be reduced by septal reduction interventions such as surgical myectomy of percutaneous alcohol septal ablation, reflecting a remodeling process affecting LV regions remote form the septum and suggesting a reversible quota of LV hypertrophy in adult patients. 14 , 15 …”

Surgical myectomy: Rationale and personalized technique

“…LV reverse remodeling occurs in all 3 layers of the myocardium at the myectomy site and in the free wall. It was found that age, disease extent, thickness of the myectomy, and sufficient relief of LVOT are important factors associated with LV remodeling 24,25 . MRI studies showed improvement in apical and midventricular systolic twist and rotation of the apical region following myectomy with unchanged basal rotations 26 .…”