Meta-Analyses of Septal Reduction Therapies for Obstructive Hypertrophic Cardiomyopathy

Long-term outcome of percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: a Scandinavian multicenter study

BACKGROUND

Single-center reports on percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy have shown considerable differences in outcome.

METHODS AND RESULTS

We report the long-term outcome of 313 PTSMA procedures performed in 279 patients with hypertrophic obstructive cardiomyopathy aged 59±14 years from 1999 to 2010 in 4 Scandinavian centers. Sixty-nine percent of patients had ≥1 comorbidity at baseline. The median (interquartile range) of left ventricular outflow tract gradient at rest was reduced from 58 mm Hg (34 to 89 mm Hg) at baseline to 12 mm Hg (8 to 24 mm Hg) at 1-year (P<0.001) and during Valsalva maneuver from 93 mm Hg (70 to 140 mm Hg) to 21 mm Hg (11 to 42 mm Hg) (P<0.001). The proportion of patients with syncope was reduced from 18% to 2% (P<0.001), and the proportion in New York Heart Association class III/IV was reduced from 94% to 21% (P<0.001). All treatment effects remained stable during the follow-up. New York Heart Association class III/IV at the most recent follow-up (2.9±2.6 years) was associated with diabetes mellitus (P=0.03), chronic obstructive pulmonary disease (P=0.02), and valve disease unrelated to hypertrophic cardiomyopathy (P<0.01). In-hospital mortality was 0.3%. The 1-, 5- and 10-year survival rates were 97%, 87%, and 67%, respectively (P=0.06 versus an age- and sex-matched background population) in all patients and 99%, 94%, and 88%, respectively (P=0.12) in patients aged <60 years (48±9 years, n=141). Age (hazard ratio, 1.07; 95% CI, 1.03 to 1.1) was the only predictor of survival.

CONCLUSIONS

In this multicenter study, the in-hospital mortality after PTSMA was low despite considerable comorbidities. The hemodynamic and symptomatic effects were sustained long term. The long-term symptomatic outcome was associated with baseline comorbidities. The 10-year survival rate was comparable to that in an age- and sex-matched background population, and age was the only predictor of survival.

Progress in perioperative echocardiography: focus on safety, clinical outcomes, 3-dimensional imaging, and education

Gastric decompression with an orogastric tube after anesthetic induction does not appear to enhance image quality for routine cases. The insertion of a transesophageal echocardiographic (TEE) probe can cause significant upper-airway trauma, which can be minimized with rigid laryngoscopy. Limited TEE imaging without transgastric views appears to be safe and clinically adequate in patients with advanced liver disease and esophageal varices. Although esophagogastric perforation because of transesophageal echocardiography is rare, the risk is significantly higher with advanced age and female sex. The echocardiographic assessment of right ventricular function and left ventricular diastolic function can improve the prediction of atrial arrhythmias after elective lung resection. Furthermore, asymptomatic left ventricular systolic or diastolic dysfunction is an independent predictor of cardiovascular mortality and morbidity after open vascular surgery. Advances in 3D echocardiography have shown that hypertrophic cardiomyopathy frequently is associated with changes in the mitral valve complex that predispose to left ventricular outflow tract obstruction. Furthermore, 3D imaging of the mitral apparatus has highlighted the importance of the annular saddle shape and the anatomic variability in ischemic mitral regurgitation. Education in perioperative echocardiography is experiencing high demand that can be satisfied partially with simulators and Internet-based educational activities. These modalities will aid in the dissemination of echocardiography through perioperative practice.

Controversies in cardiovascular medicine. Hypertrophic obstructive cardiomyopathy: alcohol septal ablation

Alcohol septal ablation (ASA) was introduced in 1994 as an alternative to septal myectomy for patients with hypertrophic obstructive cardiomyopathy and symptoms refractory to medical therapy. This procedure alleviates symptoms by producing a targeted, limited infarction of the upper interventricular septum, resulting in an increase in left ventricular outflow tract (LVOT) diameter, a decrease in LVOT gradient, and regression of the component of LV hypertrophy that is due to pressure overload. Clinical success, with improvement in symptoms and reduction in gradient, is achieved in the great majority of patients with either resting or provocable LVOT obstruction. The principal morbidity of the procedure is complete heart block, resulting in some patients in the requirement for a permanent pacemaker. The introduction of myocardial contrast echocardiography as a component of the ASA procedure has contributed to the induction of smaller myocardial infarctions with lower dosages of alcohol and, in turn, fewer complications. Non-randomized comparisons of septal ablation and septal myectomy have shown similar mortality rates and post-procedure New York Heart Association class for the two procedures.

Controversies in cardiovascular medicine. Benefits of surgery in obstructive hypertrophic cardiomyopathy: bring septal myectomy back for European patients

Hypertrophic cardiomyopathy (HCM), a heterogeneous genetic heart disease with global distribution, is an important cause of heart failure disability at any age. For 50 years, surgical septal myectomy has been the preferred and primary treatment strategy for most HCM patients with progressive, drug refractory functional limitation due to left ventricular (LV) outflow tract obstruction. With very low surgical mortality at experienced centres, septal myectomy reliably abolishes impedance to LV outflow and heart failure-related symptoms, restores quality of life, and importantly is associated with long-term survival similar to that in the general population. Nevertheless, alternatives to surgical management are necessary for selected HCM patients. For example, after a brief flirtation with dual-chamber pacing 20 years ago, percutaneous alcohol septal ablation has garnered a large measure of enthusiasm and a dedicated following in the interventional cardiology community, achieving benefits for patients, paradoxically, by virtue of producing a transmural myocardial infarct. However, an unintended consequence has been the virtual obliteration of the surgical option for HCM patients in Europe, where several robust myectomy programmes once existed. Therefore, clear differences are now evident internationally regarding management strategies for symptomatic obstructive HCM. The surgical option is now unavailable to many patients based solely on geography, including some who would likely benefit more substantially from surgical myectomy than from catheter-based alcohol ablation. It is our aspiration that this discussion will generate reconsideration and resurgence of interest in surgical septal myectomy as a treatment option for severely symptomatic obstructive HCM patients within Europe.

[Update in interventional cardiology]

This article contains a detailed review of the most important studies on interventional cardiology reported in either publications or presentations. With regard to coronary interventions, ST-elevation myocardial infarction is highlighted because of the ongoing substantial expansion in primary angioplasty programs. Drug-eluting stents, especially new-generation stents, continue to be the focus of numerous studies. Clinical outcomes in diabetic patients with left main coronary artery or multivessel disease are also dealt with by much research. In addition, intracoronary diagnostic techniques, particularly optical coherence tomography, is reviewed. Finally, there is increasing interest in the percutaneous treatment of structural heart disease, particularly percutaneous aortic valve implantation.

Alcohol Septal Ablation for the Treatment of Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an inherited myocardial disorder characterised by left ventricular hypertrophy. A subgroup of patients develops limiting symptoms in association with left ventricular outflow tract obstruction (LVOTO). Current international guidelines recommend that symptomatic patients are initially treated by alleviating exacerbating factors and negatively inotropic medication. Drug-refractory symptoms require a comprehensive evaluation of the mechanism of LVOTO and review by a multidisciplinary team to consider the relative merits of myectomy, alcohol septal ablation (ASA) and pacing. This article provides a brief overview of HCM and the pathophysiology of LVOTO, and reviews the use of ASA in patients with drug-refractory symptoms secondary to LVOTO.