Response to Letter Regarding Article, “Prevalence, Clinical Significance, and Natural History of Left Ventricular Apical Aneurysms in Hypertrophic Cardiomyopathy”
We thank Dr Giuseppe Andò et al for their interest in our description of left ventricular (LV) apical aneurysms occurring in patients with hypertrophic cardiomyopathy (HCM), a newly recognized and important subgroup within this heterogeneous disease spectrum.1 Andò et al have raised a number of important issues relative to nomenclature, mechanism, and the treatment of LV apical aneurysms in HCM patients. With respect to nomenclature, we agree that the term diverticula should be reserved for those patients with an LV apical protrusion that is congenital in origin and consists of viable myocardium.2 However, HCM patients with apical diverticula were not included in this article. Likewise, the term aneurysm should be applied to HCM patients with a discrete, thin-walled, dyskinetic or akinetic segment involving the most distal portion of the chamber, which has wide communication with the LV cavity and is associated with scarring/fibrosis of the rim and adjacent myocardium (as demonstrated in vivo with contrast-enhanced cardiac magnetic resonance).1 Because the natural history of HCM patients with apical aneurysms raises important management considerations (which may differ from other HCM patient subgroups), we agree with Andò et al that the use of proper nomenclature remains a critical issue.
A number of interesting speculations have been raised relating to the mechanism by which these apical aneurysms form in HCM patients (without coronary artery disease).3 Indeed, this area is difficult and unresolved given that, in our reported 28 patients,1 no single proposed mechanism or LV morphology seemed to explain all of the aneurysms we identified. Clearly, it is necessary to accumulate larger numbers of such aneurysm patients with serial evaluations using cardiac magnetic resonance imaging to resolve this important issue of mechanism.
Finally, given the highly adverse cardiovascular event rate in this subset of HCM patients with LV apical aneurysms, we wish to underscore the importance of considering specific treatment strategies such as the implantable cardioverter-defibrillator for primary prevention of sudden death and anticoagulation for the prevention of thromboembolic events. However, as Dr Andò and his colleagues propose, we also look forward to the future development of novel innovative treatments (eg, percutaneous aneurysm occlusion)4 that may beneficially alter the natural history of this unique subset of HCM patients.
Maron MS, Finley JJ, Bos JM, Hauser TH, Manning WJ, Haas TS, Lesser JR, Udelson JE, Ackerman MJ, Maron BJ. Prevalence, clinical significance, and natural history of left ventricular apical aneurysms in hypertrophic cardiomyopathy. Circulation. 2008; 118: 1541–1549.
Clift P, Thorne S, de Giovanni J. Percutaneous device closure of a pseudoaneurysm of the left ventricular wall. Heart. 2004; 90: e62.