NEW YORK (Reuters Health) - Higher-volume hospitals do better in treatment of obstructive hypertrophic cardiomyopathy (HCM), but more efforts are needed to direct patients to these centers, according to New York-based researchers.
In an April 27 online paper in JAMA Cardiology, they note that recommendations are that the treatments, septal myectomy (SM) and alcohol septal ablation (ASA), be performed only by experienced operators with dedicated HCM clinical programs.
"Our study demonstrates that a significant number of cases of septal myectomy and alcohol septal ablation are not being performed at centers of excellence despite the guideline," Dr. Luke K. Kim, of Weill Cornell Medical College, told Reuters Health by email.
Dr. Kim and colleagues investigated compliance and its influence on outcome by examining nationwide data from 2003 to 2009 on 6,386 patients who underwent SM and 4,862 who had ASA. During this period almost 60% of institutions performed 10 or fewer SM procedures. The corresponding proportion for ASAs was 67%.
The incidence of in-hospital death after SM was significantly lower in hospitals in the highest volume tertile (3.8%) than those in the middle (9.6%) and lowest tertiles (15.6%). Corresponding proportions for ASA were 0.6%, 0.8% and 2.3%. There was a similar pattern for acute renal failure after ASA (2.4%, 7.6% and 6.2%).
After adjustment, being in the lowest tertile of SM volume was an independent predictor of in-hospital all-cause mortality (odds ratio, 3.11) and bleeding (OR, 3.77). However, being in the lowest volume for ASA was not independently associated with an increased risk of adverse post-procedural events.
In addition, hospitalization at a high-volume center was associated with a shorter stay and lower costs for both procedures.
However, over the study period, wrote the investigators, "Most centers that provide septal reduction therapy performed few SM and ASA procedures" and were "below the threshold recommended."
In particular, they concluded "Low SM volume was associated with worse outcomes, including higher mortality, longer length of stay, and higher costs. More efforts are needed to encourage referral of patients to centers of excellence for septal reduction therapy."
Commenting on the findings by email, Dr. Steve R. Ommen, coauthor of an accompanying invited opinion, told Reuters Health that "patients deserve to be offered the best care and outcomes possible and that appears to be possible only at centers with focused expertise in the management of HCM. Simply being a high-volume facility does not translate into achieving the safety nor the success observed at expert centers."
Dr. Ommen of the Mayo Clinic, Rochester, Minnesota, added that "Success takes a comprehensive understanding of the underlying HCM disease process. That is really the main take-home message from my point of view."
The other really astonishing finding," he concluded, "was that the median number of procedures performed was only one per year per hospital in the study."
The Michael Wolk Heart Foundation and the New York Cardiac Center supported this research. Two coauthors reported disclosures.