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

Ismail El-Hamamsy,Franco Cecchi,Karim Lekadir,Robert Merrifield,Magdi H Yacoub,Guangzong Yang,Iacopo Olivotto,Ahmed El Guindy,Luigi Rega

doi:10.5339/gcsp.2012.9

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±29g/m2 versus 154±36g/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.

Highlights

Hypertrophic cardiomyopathy (HCM) is a heterogeneous genetic disease which can present with a wide spectrum of phenotypic manifestations affecting the interventricular septum, the ventricular muscle, the mitral valve, the subvalvular apparatus and the papillary muscles [1,2,3,4]
In conclusion, this study demonstrates that the use of a tailored surgical approach for the treatment left ventricular outflow tract (LVOT) dysfunction in patients with HCM results in a diffuse and heterogeneous pattern of regional left ventricle (LV) remodelling
This is characterized by a decrease in wall thickness in all segments of the LV along with an increase in thickening at rest in the basal septal segments

Summary

Introduction

Hypertrophic cardiomyopathy (HCM) is a heterogeneous genetic disease which can present with a wide spectrum of phenotypic manifestations affecting the interventricular septum, the ventricular muscle, the mitral valve, the subvalvular apparatus and the papillary muscles [1,2,3,4]. These abnormalities can result in dysfunction of the left ventricular outflow tract (LVOT) resulting in dynamic LVOT obstruction [5], which is identified in up to 70% of subjects with HCM [6]. The specific aspect of regional LV response in structure and function following surgical myectomy has not been studied before

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