SEATTLE, WA — Renal failure is widely recognized as a leading predictor of poor prognosis after cardiac surgery, but new research details just how grim that prognosis is following left ventricular assist device (LVAD) placement[1].
In a cohort of Medicare beneficiaries, less than half (48.4%) of patients with end-stage renal disease (ESRD) survived to discharge after LVAD placement, with a median time to death of only 16 days.
By comparison, 96% of patients without ESRD survived to discharge after pump surgery, and their median survival was nearly 6 years (2125 days), according to a report published online December 18, 2017 in JAMA Internal Medicine.
“The value of this study is not so much to say whether or not patients should get these [devices], but if you’re considering this, this is what you can expect,” senior study author Dr Ann M O’Hare (VA Palo Alto Health Care System, CA) told theheart.org | Medscape Cardiology.
“I think most people would not consider a median survival of less than 3 weeks to be a meaningful benefit, but it’s a median value, so there were outliers,” she added. “There are people who do survive and in fact there were even some who made it to heart transplant.”
In all, nine (5.8%) patients with ESRD went on to receive a heart transplant vs 56 (25%) patients without ESRD.
“The data do speak for themselves, but it always makes me a little worried to see rigidity in how we interpret data,” O’Hare said. “The point is that population-level data should inform the conversation with the patient and their family.”
While trials such as INTREPID and REMATCH have shown a survival benefit with LVADs in transplant-ineligible patients, few studies have examined outcomes in LVAD patients with kidney disease. One strength of the present study is that they were able to identify with a high degree of accuracy LVAD patients with ESRD, defined as maintenance dialysis or kidney transplant, O’Hare said.
The analysis included 155 patients identified in the US Renal Data System (USRDS), a national registry for ESRD, linked to Medicare claims for a first LVAD placement between 2003 and 2013 and 261 patients without ESRD identified from the 5% Medicare sample who received an LVAD during the same time period.
ESRD patients were more likely to be black than those without ESRD (37.4% vs 20.3%) and to have more comorbidities (nine vs six). Their mean ages were 58.4 and 62.2 years, respectively.
One year after LVAD placement, 75.2% of the 155 patients with ESRD had died vs 20.1% of the 261 patients without ESRD.
After adjustment for demographics, comorbidity, and time from LVAD placement, patients with ESRD continued to have a higher adjusted risk of death (hazard ratio 36.3, 95% CI 15.6–84.5), particularly in the first 60 days after LVAD placement, according to the researchers, led by Dr Nisha Bansal (University of Washington, Seattle).
They note that the study has several limitations, chief among them the lack of detailed information on the clinical context in which the LVADs were placed, the indication for LVAD placement, or type of LVAD used.
In a related editorial[2], Drs Sunu S Thomas, Emily K Zern, and David D’Alessandro (Harvard Medical School, Boston, MA) write that such information is critical to understand the “exceptionally high mortality rate and the appropriateness of LVAD therapy in a recognized marginal [mechanical circulatory support] MCS candidate population.”
The editorialists also express surprise that the study reports a near-doubling of ESRD patients treated with presumed durable LVAD therapy from 2003 to 2007 and 2010 to 2013, whereas registry data have shown that only 5.7% of patients implanted with a continuous-flow LVAD from 2006 to 2012 had severe renal dysfunction.
One explanation for the “seemingly indiscriminate use of implantable LVADs in the current study” is that ICD-9 codes used to identify the study cohort “may not accurately differentiate temporary from permanent circulatory support devices,” Thomas and colleagues write.
Current MCS guidelines recommend against LVAD destination therapy in patients requiring permanent dialysis.
Renal recovery occurred in 12 ESRD patients after LVAD placement, but the editorialists note that 82% of the ESRD cohort was already committed to chronic renal-replacement therapy (75% hemodialysis; 7.3% peritoneal dialysis), “rendering any potential for a clinically meaningful improvement in renal function to be limited, particularly with a time interval between ESRD diagnosis and LVAD implantation of more than 4 years.”
The short survival time, O’Hare said, suggests that “either the devices were placed and the procedures were offered at a time when the patient was actively dying or the actual procedure and care that went along with that and any complications triggered death.”
She said patients on dialysis in general tend to receive quite intensive interactions very close to the end of life and that rates of hospice in this population are about half the rate in the general Medicare population.
Among study patients who survived the index hospitalization, less than 10 in each group (with and without ESRD) received hospice care.
“There’s a lot of interest in this now, and widespread recognition in the renal community that we need to do a better job of integrating palliative care in the course of the illness, but that’s a work in progress,” O’Hare said.
The research was supported by the National Institute of Diabetes and Digestive and Kidney Diseases. The authors and editorialists report no relevant financial relationships.
Follow Patrice Wendling on Twitter: @pwendl. For more from theheart.org | Medscape Cardiology, follow us on Twitter and Facebook.
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