Hospital Volume Linked to More Favorable LAA Closure Outcomes

In-hospital adverse outcomes following percutaneous left atrial appendage (LAA) closure are more frequent in real-world practice than in clinical trials, but the risks are mitigated at hospitals with higher procedure volumes, according to a study published online December 5, 2014, ahead of print in Circulation: Arrhythmia and Electrophysiology. Closures performed at higher-volume centers also come with shorter hospital stays and lower costs.

Juan F. Viles-Gonzalez, MD, of the University of Miami Hospital (Miami, FL), and colleagues examined data from the Nationwide Inpatient Sample on 268 percutaneous LAA closures performed for the prevention of stroke in patients with A-fib (mean age 70) from 2006 to 2010. The researchers were unable to differentiate among the technologies deployed, which included the investigational Watchman device (Boston Scientific), the Amplatzer cardiac plug (St. Jude Medical), and the Lariat suture device (SentreHeart), because of the use of a single ICD-9 code for all procedures.

Mean length of stay was 4.61 days, and the mean cost of care was $26,024.

A Range of Complications Observed

About one-quarter of patients (24.3%) either died—the mortality rate was 2.3%—or had a complication in the hospital, with 3.4% requiring open cardiac surgery because of complications.

The most frequent complications were cardiac (12.4%), a category that included iatrogenic problems like postoperative arrhythmias and cardiac arrest (6.8%), complete heart block (3.8%), issues related to a heart prosthesis (2.3%), and pericardial complications (1.7%).

Other common complications were respiratory difficulties (5.7%); vascular issues (4.5%), mostly related to postoperative hemorrhage requiring transfusion; postoperative stroke or TIA (3.3%); and renal and metabolic complications (< 0.5%).

Patients tended to fare better at higher-volume hospitals. On multivariable analysis, each unit increase in annual procedure volume was associated with a lower rate of mortality and complications (OR 0.89; 95% CI 0.85-0.94), a shorter length of stay (HR 0.95; 95% CI 0.92-0.98), and a lower cost of care (HR 0.96; 95% CI 0.93-0.98).

After hospitals were divided into tertiles based on volume, those with highest volume (at least 18 percutaneous LAA closures each year) had a reduced rate of death or complications compared with those with the lowest volume at 3% vs 46% (P < .001). The relationships were similar for length of stay and cost of care.

Use of intracardiac echocardiography—employed in 6.6% of procedures—was associated with reduced length of stay (HR 0.44; 95% CI 0.30-0.66) but did not affect cost or in-hospital outcomes.

A greater number of comorbidities correlated with a greater risk of complications or death, longer lengths of stay, and higher costs.

Real World vs Clinical Trials

Much of the safety data on percutaneous LAA closure devices comes from clinical trials and might not reflect what happens in daily practice, the authors say. Even though the mortality rate in this study (2.3%) is lower than rates seen in the PROTECT AF trial of the Watchman device (3.2%) and a recent observational study of the Amplatzer cardiac plug (5.8%), the combined rate of mortality and complications is higher than reported in prior studies.

“We have included a more comprehensive and a broader range of complications (including infections, [deep vein thrombosis], pressure ulcer, and renal failure) in our study, which could explain this higher complication rate,” Dr. Viles-Gonzalez and colleagues note.

The finding that higher-volume hospitals had better outcomes, however, was concordant with results from PROTECT AF and the Continued Access Protocol registry.

“Given the ever-increasing economic burden of health care spending in the [United States], this finding suggests that perhaps percutaneous LAA closure, like other complex and highly technical procedures, should be performed only by centers and operators that can maintain an acceptable volume threshold,” the authors write.

Source:

Badheka AO, Chothani A, Mehta K, et al. Utilization and adverse outcomes of percutaneous left atrial appendage closure for stroke prevention in atrial fibrillation in the United States: influence of hospital volume. Circ Arrhythm Electrophysiol. 2014;Epub ahead of print.

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