Following discharge from hospital after acute kidney injury (AKI), among patients who were seen in an AKI follow-up clinic, all-cause mortality was 29% lower and there were 23% fewer cardiovascular events compared with patients who received standard care during a mean 2.2-year follow-up.
Patients seen in the AKI follow-up clinic also received more prescriptions for some cardioprotective medicines, but the risk of subsequent kidney events was similar in both groups.
The study by Samuel A. Silver, MD, Queen’s University, Kingston, Ontario, and colleagues was published online December 12 in the American Journal of Kidney Disease.
“Patients who are discharged from hospital after surviving an AKI are a high-risk population,” Silver wrote in an email to Medscape Medical News. “The short- and long-term health consequences of surviving a hospitalization with AKI are underrecognized,” he said, “as are the current gaps in follow-up care.”
The findings illustrate some potential benefits of an AKI follow-up clinic, he summarized.
However, this was a single-center study, and there may have been residual confounding, so “these results should still be viewed as hypothesis-generating and need to be confirmed in large studies and randomized trials,” he cautioned.
“But my hope is that these results will stimulate enthusiasm amongst nephrologists and other health care providers about the potential benefits and importance of post-AKI care,” Silver added.
“More Active Role” Needed in Post-AKI Care
“I think nephrologists need to take a more active role in post-AKI care,” he elaborated. “Even though nephrologists cannot assess every patient who survives AKI, we can still take ownership of post-AKI care systems and support acute care and primary care providers in ensuring that risk stratification, discharge communication, tests, and appropriate cardioprotective therapies actually happen.”
For example, Silver said, at his hospital, Kingston Health Sciences Centre, in Ontario, within 1 to 2 weeks after a patient has been discharged from hospital after AKI, primary care providers receive a one-page letter informing them that their patient had had an AKI.
The letter explains that the patient is at increased risk of a cardiac event, tells them how to monitor the patient, and provides a telephone number for assistance with any questions they may have.
AKI follow-up clinics have become somewhat more common since 2013, Silver observed. He estimates that 25% to 30% of centers in high-income countries now have these clinics.
There are few evidence-based treatments to attenuate chronic kidney disease (CKD) progression, he noted, except for sodium-glucose cotransporter-2 (SGLT2) inhibitors and angiotensin-converting enzyme inhibitors (ACE inhibitors)/angiotensin receptor blockers (ARBs) for patients with diabetes and proteinuria.
“Transition from AKI to CKD is an active area of research, and we desperately need more treatment strategies to protect the kidneys in this high-risk population,” he added.
AKI Diagnosis Absent in >50% of Discharge Summaries
AKI is associated with new or worsening CKD, end-stage kidney disease, and new-onset hypertension and cardiovascular disease, but there are many gaps in follow-up care of such patients, the researchers note.
Perhaps shockingly, “in current practice, less than 50% of discharge summaries document the presence of AKI, and over 80% of hospitalized patients are unaware that they experienced AKI,” Silver and colleagues observe.
“These gaps may explain why less than 15% of patients have kidney function and proteinuria assessed within 90 days of an AKI episode, as is suggested by Kidney Disease Improving Global Outcomes (KDIGO) AKI guidelines,” they write, and “only 5-10% of these patients see a nephrologist within 90-days of hospital discharge.”
The researchers hypothesize that attendance at an AKI clinic would lower the risk of adverse kidney events, would lead to more frequent kidney function monitoring, and would increase the likelihood of patients being prescribed cardioprotective medications.
They performed a retrospective cohort study of 164 patients who survived a hospitalization with AKI from February 2013 to September 30, 2017, and who attended the AKI follow-up clinic at St. Michael’s Hospital in Toronto, Ontario, Canada, within 6 months of hospital discharge. Each of these patients was matched with four similar patients in Ontario who received standard care.
In the propensity-score matched cohort, the mean age of the patients was 66 years; 32% were women; 77% had hypertension; 14% had had a myocardial infarction; 38% had cancer; 75% were taking statins; and 90% had visited a primary care provider 90 days prior to the AKI episode.
About 27% of the patients had stage 1 AKI, 31% had stage 2 AKI, and 42% had stage 3 AKI.
The patients who were seen in the AKI follow-up clinic met with a nephrologist who emphasized reducing blood pressure, proteinuria, and cardiovascular risk factors and who provided guidance on the management of CKD complications.
The patients also received a list of medications that should not be taken if they were to experience diarrhea or vomiting or were unable to eat or drink, and they were also given requisitions for lab tests that were to be conducted every 3 months for a year.
The primary outcome was time to a major adverse kidney event, defined as death, initiation of maintenance dialysis, or incident/progressive CKD.
Secondary outcomes included the individual components of the primary composite outcome, as well as major adverse cardiovascular events and measures of care after AKI.
Over a mean follow-up of 2.2 years, care in the AKI clinic was not associated with significantly fewer major adverse kidney events compared to standard care (22.1 vs 24.7 events per 100 patient-years; hazard ratio [HR], 0.91; 95% CI, 0.75 – 1.11).
However, treatment in the clinic was associated with a lower risk of all-cause mortality (HR, 0.71; 95% CI, 0.55 – 0.91).
Patients who were aged 66 years or older and who attended the AKI follow-up clinic were more likely to receive beta blockers (HR, 1.34; 95% CI, 1.02 – 1.77) and statins (HR, 1.35; 95% CI, 1.05 – 1.74) but not ACE inhibitors or ARBs (HR, 1.21; 95% CI, 0.94 – 1.56).
The study was supported by the Ontario Renal Network through funding provided by the Government of Ontario and was also supported by the ICES Western site. Silver has received speaking fees from Baxter Canada. Another author has received grant support and speaking fees from Baxter. The remaining authors have disclosed no relevant financial relationships.
Am J Kidney Dis. Published online December 12, 2022. Abstract
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