Delirium is more common in patients undergoing surgical rather than transcatheter aortic valve replacement (SAVR, TAVR) but predicted worse in-hospital outcomes after both procedures, a new study suggests.
"Patients experience delirium fairly frequently after aortic valve replacement, whether transcatheter or surgical, but we found that it happens more often after surgical replacement," coauthor Amar Krishnaswamy, MD, Cleveland Clinic, Ohio, told theheart.org | Medscape Cardiology.
"When analyzing patients for one type of replacement compared to another, I think it's important to consider whether their underlying medical conditions raise their risk of delirium and whether or not that should affect the treatment strategy."
The results were reported online August 2 in JACC: Cardiovascular Interventions.
Previous studies have reported on the incidence and predictors of postoperative delirium (POD) following TAVR, but data comparing POD rates after TAVR and SAVR in those studies are limited to small sample sizes.
For the present study, the researchers identified 624,303 hospitalizations for valve replacement from 2012 to 2017 in the Nationwide Readmissions Database, of which 3.97% had delirium. Patients in the TAVR group were older (80.6 years vs 67.6 years) and had more significant comorbidities.
POD developed in 4.38% of TAVR patients and 3.79% of SAVR patients. After adjusting for patient characteristics, however, delirium was less likely after TAVR than SAVR (adjusted odds ratio [aOR], 0.76; 95% CI, 0.72 - 0.81).
"The less invasive a procedure is, the less stressful it is for the patient in general. And so we see that the incidence of delirium is much lower," Alan Zajarias, MD, of Washington University School of Medicine in St. Louis, Missouri, who was not involved with the study, told theheart.org | Medscape Cardiology.
Dementia was the most important predictor of delirium for patients who underwent TAVR (aOR, 71.65; 95% CI, 65.65 - 78.24) or SAVR (aOR, 8.68; 95% CI, 7.94 - 9.48).
Other significant predictors of delirium after TAVR were: stroke (aOR, 3.34), acute kidney injury (aOR, 2.33), weight loss (aOR, 2.11), electrolyte disturbances (aOR, 1.30), and blood transfusion (aOR, 1.16).
For SAVR, other significant predictors were: prior neurologic disease (aOR, 2.82), weight loss (aOR, 2.26), acute kidney injury (aOR, 2.01), stroke (aOR, 1.98), electrolyte disturbances (aOR, 1.55), chronic liver disease (aOR, 1.40), and heart failure (aOR, 1.22).
Elective admission and female sex were associated with decreased rates of POD in both groups, the authors reported.
For patients who experienced POD vs those who did not, in-hospital mortality and length of hospitalization were significantly worse.
After TAVR, POD was associated with increased in-hospital mortality (5.06% vs 2.23%) and prolonged hospitalization (9.92 days vs 5.98 days; P < .001 for both).
After SAVR, POD was also associated with higher in-hospital mortality (8.21% vs 3.43%) and prolonged hospitalization (19.58 vs 10.65 days; P < .001 for both).
Many factors that raise the risk of delirium, such as chronic medical conditions, are difficult to control. However, there are still risk-lowering measures that can be taken to help improve patient outcomes, Krishnaswamy said.
"Minimizing sedatives in patients undergoing AVR can be helpful. The use of embolic protection devices can not only reduce the risk of stroke but may also reduce the risk of delirium. Optimizing procedural pathways to get patients moving and out of the hospital as soon as possible is important, especially for elderly patients," said Krishnaswamy.
The overall rate of delirium of about 4% was lower than rates observed in prior studies, which "reported delirium rates ranging from 25% to 66% after major cardiac surgery and from as low as 2% to as high as 44% after TAVR," wrote first author Agam Bansal, MD, Cleveland Clinic, and colleagues.
This may be in part due to a key limitation of the study, which is its retrospective, nonrandomized design and reliance on International Classification of Diseases codes rather than prospective monitoring of cognitive outcomes in patients.
"Claims data tends to underreport the actual incidence of delirium by a factor of two or three," Parthasarathy Thirumala, MD, of the University of Pittsburgh School of Medicine, who was not involved in the study, said in an interview.
For future research, using "active screening for delirium rather than a diagnostic code is very important," Zajarias said.
Krishnaswamy, Zajarias, Bansal, and Thirumala have disclosed no relevant financial relationships.
JACC Cardiovasc Interv. 2021;14:1738-40. Full text
Anna Goshua is a reporting intern with Medscape. She is a dual medical and journalism student who has previously written for STAT, Scientific American, Slate, and other outlets. She can be reached at firstname.lastname@example.org or @AnnaGoshua.
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Cite this: Anna Goshua. Delirium Less Likely After TAVR Than Surgical Valve Replacement - Medscape - Aug 03, 2021.