麻豆传媒

Patients who developed late right heart failure (RHF) after left ventricular assist device (LVAD) surgery suffered more major adverse events and had worse survival, researchers found.

At 1 month post-LVAD placement, 19% of patients met criteria for moderate RHF, a figure that fell to 5% at 3 months (when another 5% had mild RHF), reported Jeffrey Teuteberg, MD, of Stanford University in California, and colleagues analyzing over 6,000 people from the Society of Thoracic Surgeons Intermacs database.

Compared with peers who had late RHF, LVAD recipients without RHF at 3 months tended to have better clinical outcomes by 12 months:

• Mortality: 6.9% with no RHF vs 16.7% with mild RHF vs 28.1% with moderate RHF (P<0.0001)

• Stroke: 7.4% vs 9.5% vs 11.0% (P=0.0095)

• Gastrointestinal bleeding: 14.8% vs 24.2% vs 23.6% (P<0.0001)

• Rehospitalization: 65.2% vs 73.2% vs 71.2% (P<0.0001)

"Strategies to protect patients from post-LVAD RHF and lead to improvements in right ventricular [RV] function and reserve are essential to improving long-term outcomes with mechanical circulatory support," Teuteberg's group wrote in the study online in the .

"Despite the possibility of transplant as a solution to persistent RHF, the competing outcomes analysis did not show a higher proportion of patients being transplanted by 12 months when assessed by RHF status at 3 months. This is possibly a reflection of the impact of late RHF on end-organ function, rehabilitation, frailty, or other concomitant comorbidities or adverse events, which may influence transplant candidacy," the authors noted.

They listed volume management, guideline-directed medical therapy for heart failure, therapies for pulmonary hypertension, and management of the LVAD itself as potential strategies to treat or prevent late RHF. Neurohormonal blockade may also help, though the existing data are unclear, the team said.

For now, a major challenge appears to be the prediction of early RHF after LVAD surgery.

"Although it was hoped that effective unloading of the failing left ventricle (LV) with LVADs would adequately unload the RV as well, only minor improvement in RV function is reported by 3 months after LVAD implantation," commented Lynne Warner Stevenson, MD, and colleagues, all of Vanderbilt University Medical Center in Nashville, in an . "Our understanding of RHF before and after LVAD is clouded by the difficulties of imaging the RV, wherein the irregular bananoid shape and prominent trabeculations defy quantification. More routine access to 3-dimensional imaging may facilitate RV assessment during rest and stress."

The study included 6,118 Intermacs registry participants who were supported with a continuous-flow LVAD for at least 3 months with no simultaneous RVAD. Mean age was 56.7 years, and nearly four in five patients were men. White individuals accounted for 64.6% of the cohort.

Historically, early postoperative RHF had been informally defined as the need for an RVAD or prolonged postoperative inotropes.

In the present study, patients with RHF had to have evidence of both manifestations of elevated central venous pressure (CVP) and documentation of elevated CVP, in line with the consensus definition of RHF adopted in 2014.

Teuteberg's team reported that the prevalence of mild and moderate RHF at 12 months was 6% and 3%, respectively. People with no RHF at 3 months stayed free of subsequent RHF at 6 and 12 months in 93% of cases. In contrast, among those with mild or moderate RHF at 3 months, about one-third of patients had recurrent RHF between 6 and 12 months.

Late RHF was not associated with worse quality of life, as defined by a visual acuity scale, in the first year after LVAD placement.

Major limitations of the study, the researchers said, were the inclusion of only patients who survived to 3 months post-implant and the lack of information on exact time of RHF development or RHF recurrence.

"Nevertheless, the data presented highlight the need to identify and target clinical strategies directed at maintaining reasonable RV filling pressures, improving or preserving RV function, treating elevated pulmonary vascular resistance, and optimally managing pump function to further decrease the risk of late RHF," Teuteberg and colleagues said.

Even when patients appear stable, persistent elevation of pulmonary pressures may warrant more aggressive intervention, the editorialists said. "We need to change the trajectory of disease before the RV reaches the tipping point that jeopardizes the outcomes with both medical therapy and LVADs."

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