Chronic Kidney Disease Tied to Worse LAAO Outcomes

Patrice Wendling

August 17, 2021

The presence of chronic kidney disease (CKD) or end-stage renal disease (ESRD) is associated with worse in-hospital and short-term outcomes after left atrial appendage (LAA) closure, a nationwide study shows.

Patients with ESRD were particularly vulnerable, having about 6.5-fold higher odds of in-hospital mortality than those without CKD and about 11.5-fold higher odds than those with CKD, even after adjustment for potential confounders.

Patients with CKD had higher rates of stroke or transient ischemic attack (TIA) and more short-term readmissions for bleeding, Keerat Rai Ahuja, MD, Reading Hospital-Tower Health, West Reading, Pennsylvania, and colleagues reported August 16 in JACC: Cardiovascular Interventions.

CKD and ESRD are known to be associated with an increased risk for stroke and bleeding in patients with atrial fibrillation (AF), yet data are limited on the safety and efficacy of LAA closure for stroke prevention in AF patients with CKD or ESRD, they note.  

"It's important to know about CKD and understand that there may be an association with worse levels of CKD and worse outcomes, but the data that strikes me is really that for end-stage renal disease," Matthew Sherwood, MD, MHS, who was not involved with the study, said in an interview with | Medscape Cardiology.

He noted that data have not been published for patients with CKD and ESRD enrolled in the pivotal PROTECT-AF and PREVAIL trials of Boston Scientific's Watchman device or from large clinical registries such as EWOLUTION and the company's continued access protocol registries.

Further, it's not well understood what the best strategy is to prevent stroke in AF patients with ESRD and whether they benefit from anticoagulation with warfarin or any of the newer agents. "Thus, it's hard to then say: 'well they have worse outcomes with Watchman,' which is true as shown in this study, but they may not have any other options based upon the lack of data for oral anticoagulants in end-stage kidney disease patients," said Sherwood, from the Inova Heart and Vascular Institute, Falls Church, Virginia.

The lack of clarity is concerning, given rising atrial fibrillation cases and the prevalence of abnormal renal function in everyday practice. In the present study — involving 21,274 patients undergoing LAA closure between 2016 and 2017 in the Nationwide Readmissions Database — 18.6% of patients had CKD stages I to V and 2.7% had ESRD based on ICD-10 codes.

In-hospital mortality was increased only in patients with ESRD. In all, 3.3% of patients with ESRD and 0.4% of those with no CKD died in hospital (adjusted odds ratio [aOR], 6.48), as did 0.5% of patients with CKD (aOR, 11.43; both P <.001).

"These patients represent a sicker population at baseline and have an inherent greater risk for mortality in cardiac interventions, as noted in other studies of structural heart interventions," Ahuja and colleagues write.

Patients with CKD had a higher risk for in-hospital stroke or TIA than patients with no CKD (1.8% vs 1.3%; aOR, 1.35; P = .038) and this risk continued up to 90 days after discharge (1.7% vs 1.0%; aOR, 1.67; P = .007).

The in-hospital stroke rate was numerically higher in patients with ESRD compared with no CKD (aOR, 1.18; P = .62).

The authors point out that previous LAA closure and CKD studies have reported no differences in in-hospital or subsequent stroke/TIA rates in patients with and without CKD. Possible explanations are that patients with CKD in the present study had higher CHA2DS2-VASc scores than those without CKD (4.18 vs 3.62) and, second, patients with CKD and AF are known to have higher risk for thromboembolic events than those with AF without CKD.

CKD patients were also more likely than those without CKD to experience in-hospital acute kidney injury or hemodialysis (aOR, 5.02; P <.001).

CKD has been shown to be independently associated with acute kidney injury (AKI) after LAA closure. AKI may have long-term thromboembolic consequences, the authors suggest, with one study reporting higher stroke risk at midterm follow-up in patients with AKI.

"As with other cardiac interventions in patients with CKD, efforts should be made to optimize preoperative renal function, minimize contrast volume, and avoid abrupt hemodynamic changes such as hypotension during the procedure to prevent AKI," Ahuja and colleagues write.

Patients with CKD and ESRD had longer index length of stay than those without CKD, but had similar rates of other in-hospital complications such as systemic embolization, bleeding/transfusion, vascular complications, and pericardial tamponade requiring intervention.

Among the short-term outcomes, 30- and 90-day all-cause readmissions were increased in patients with CKD and ESRD compared with those without CKD; and 30-day bleeding readmissions were increased within the CKD cohort.

"With Watchman and left atrial appendage closure what we see is that they have higher rates of readmission and other problems," Sherwood said. "I think we understand that that's probably related not to the procedure itself, not because the Watchman doesn't work for end-stage kidney disease, but because the patients themselves are likely higher risk."

Commonly used risk scores for atrial fibrillation, however, don't take into account advanced kidney disease, he added.

Besides the inherent limitations of observational studies, Sherwood and the authors point to the lack of laboratory variables and procedural variables in the database, CKD was defined using ICD-10 codes, outcomes were not clinically adjudicated, unmeasured confounders likely still exist, and long-term follow-up is lacking.

Sherwood, who wrote an editorial accompanying the study, said that the release of outcomes data from CKD and ESRD patients in the major clinical trials would be helpful going forward, as would possible involvement with the Kidney Disease Improving Global Outcomes organization.

"One of the main points of this study is that we just need a lot more research diving into this patient population," he said.

The authors report no relevant financial relationships. Sherwood reports honoraria from Janssen and Medtronic. Editorial coauthor Sean Pokorney reports research grant support from Gilead, Boston Scientific, Pfizer, Bristol Myers Squibb, Janssen, and the US Food and Drug Administration; and advisory board, consulting, and honoraria supports from Medtronic, Boston Scientific, Pfizer, Bristol Myers Squibb, Philips, and Zoll.

J Am Coll Cardiol Intv. 2021;14:1830-1839 and 1840-1842  Abstract, Editorial

Follow Patrice Wendling on Twitter: @pwendl. For more from | Medscape Cardiology, join us on Twitter and Facebook.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.