Conference Coverage

PAP sensor may cut real-world heart failure hospitalization

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Study flaws undermine strength of evidence

Real-world evidence about the PAP sensor is particularly important, because the FDA approved the device amid considerable controversy over the CHAMPION trial and its sponsor. Employees of the sponsor were considered to have contaminated the initial data, and the FDA initially rejected the device. Substantial uncertainty still persists concerning the sensor’s effectiveness in reducing HF hospitalizations.

In addition, the percentage of HF patients who have received the device is extremely small, given that the study and the highly selected patient sample make both causal inferences and generalizability of the findings difficult.

Dr. Harlan Krumholz director of Yale New Haven Health System

Dr. Harlan Krumholz

Most important, the pre/post implantation design of this study is weak, because many other interventions may have been taking place during the study period with the goal of keeping implanted patients out of the hospital. Indeed, it is likely that the device was only part of a multipronged strategy to reduce HF hospitalizations. And the implantation itself certainly led to greater involvement of a health care team in the patients’ care.

The net effect of these important limitations is that the study by Desai et al. lacks the strength to change prior assumptions about the PAP sensor’s benefits in any direction. Unfortunately, this study doesn’t have the evidentiary robustness to inform clinical decisions.

Harlan M. Krumholz, MD, and Sanket S. Dhruva, MD, are both in the Robert Wood Johnson Foundation Clinical Scholars Program and at the Yale School of Medicine and Yale School of Public Health in New Haven, Conn. Dr. Krumholz reported ties to Johnson & Johnson and Medtronic; Dr. Dhruva reported having no relevant financial disclosures. They made these remarks in an editorial accompanying the study (J Am Coll Cardiol. 2017 Mar 19. doi:10.1016/j.jacc.2017.03.019).


 

FROM ACC 17

Implantation of a pulmonary artery pressure sensor to guide care in chronic heart failure was associated with a significant 45% reduction in HF hospitalization and its attendant substantial costs in a real-world patient population, Akshay S. Desai, MD, said at the annual meeting of the American College of Cardiology.

Dr. Akshay S. Desai of Brigham and Women’s Hospital, Boston.

Dr. Akshay S. Desai

In a manufacturer-sponsored retrospective observational study using Medicare claims data, investigators compared the rate of HF hospitalizations during the 6 months preceding sensor implantation against that during the 6 months following implantation in 1,114 patients.

Their intention was to determine whether the positive results of the CHAMPION clinical trial, which prompted FDA approval of the device as a means to reduce HF-associated hospitalizations, could be replicated in a real-world population, said Dr. Desai of Brigham and Women’s Hospital, Boston.

The results of their study were presented March 19 at the annual meeting of the American College of Cardiology and simultaneously published online in the Journal of the American College of Cardiology (2017 Mar 19. doi: 10.1016/j.jacc.2017.03.009).

The mean age of the study cohort was 71 years, and 40% of the participants were at least 75 years of age. Women composed 40% of the cohort. There was a high burden of comorbid illness, including diabetes, hypertension, and chronic obstructive pulmonary disease. This represents a broader sample than was enrolled in the CHAMPION trial, he noted.

There were 1,020 HF hospitalizations before implantation and 381 afterward. A total of 59% of patients had at least one HF hospitalization before the PAP implantation, compared with 22% afterward. The median number of HF hospitalizations was 0.92 per patient before implantation and 0.37 per patient afterward.

Further analysis showed that the cumulative rate of HF hospitalization was 45% lower during the 6 months after implantation than during the 6 months preceding it (hazard ratio, 0.55). This finding remained robust across several subgroups of patients and in several sensitivity analyses.

These reductions were associated with a corresponding decline in costs related to HF care, which dropped by $7,433 per patient.

In addition to HF-related hospitalizations, all-cause hospitalizations also declined by roughly 30% after implantation of a PAP sensor (HR, 0.69).

These findings suggest that the reduction in hospitalizations, along with attendant reductions in the costs of care, may be achievable in real-world practice. The 45% drop in HF hospitalizations in this study “compares favorably with the 28% reduction seen with PAP-guided therapy over the same time period in the randomized CHAMPION study that supported the initial FDA approval,” Dr. Desai said.

Moreover, a subgroup of 480 patients had data for 12 months preceding and 12 months following implantation. Analysis of those data showed that the benefits of PAP monitoring to guide HF care “were consistent over longer-term follow-up, with a 34% reduction in HF hospitalizations sustained at 12 months,” he added.

The study had several limitations. It excluded Medicare Part D data, so medication changes related to implantation could not be examined and may have exerted substantial influence on study outcomes.

It also didn’t include the actual PAP-sensor data, “which makes it challenging to confirm that physicians intervened to treat elevated PAPs” and that that intervention is the reason for the study outcomes.

“We were unable to definitively ascertain whether reduced HF hospitalizations are related to undertreatment in the preimplant period or improved treatment in the postimplant period,” Dr. Desai said.

The study was sponsored by Abbott, maker of the CardioMEMS PAP sensor. Dr. Desai and his associates reported ties to Abbott and St. Jude Medical.

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