Delirium Common Following Aortic Valve Replacement, Tied to Increased Mortality

Delirium is commonly seen in the intensive care unit (ICU) after both surgical and transcatheter aortic valve replacement and raises the likelihood that patients will die in their first postoperative year, according to a study presented on April 27, 2015, at the American Association for Thoracic Surgery Annual Meeting in Seattle, WA. In addition, patients with delirium have longer stays in the ICU and hospital.

The study, presented by Hersh S. Maniar, MD, of Washington University School of Medicine (St. Louis, MO), included patients who underwent transcatheter aortic valve replacement (TAVR; n = 168) or surgical aortic valve replacement (SAVR; n = 259) between 2008 and 2013. While recovering in the ICU, all were screened for delirium twice a day with the Confusion Assessment Method for the ICU (CAM-ICU).

Delirium was detected in 33% of SAVR patients and 29% of TAVR patients (P = .40).

The factors associated with delirium differed by procedure type. Older age (P = .01) and intubation time longer than 24 hours (P < .05) signaled a higher risk in the SAVR group, and chronic systemic steroid use (P = .03), nontransfemoral access (P < .05), and acute kidney injury (P = .04) predicted greater risk in the TAVR group.

Patients with vs without delirium were more likely to die within 30 days and 1 year. Delirium also was associated with a longer initial ICU stay and overall hospital stay, as well as a higher ICU readmission rate (table 1).

After adjustment for age, sex, Society of Thoracic Surgeons (STS) score, and type of valve replacement, delirium remained associated with 1-year mortality (HR 3.02; 95% CI 1.75-5.23), a relationship observed in both SAVR and TAVR patients.

An Under-recognized Problem

It is known that delirium is a frequent complication after cardiac procedures, but it is often overlooked and undertreated, according to Jesse Raiten, MD, of the Hospital of the University of Pennsylvania (Philadelphia, PA).

The cause of delirium in cardiac patients is likely multifactorial, he told TCTMD in a telephone interview. TAVR patients in particular tend to be older and to have multiple comorbidities, which places them at risk for postoperative delirium. Other factors, including medications, anesthesia, and the ICU environment, also play a role, he said.

Dr. Raiten said the amount of attention paid to delirium in the ICU can depend on whether patients have the hyperactive form, which can involve pulling out IVs or creating risk for themselves or others, or the hypoactive form, which can include withdrawal and confusion without acting out in a risky fashion. The latter form is often attributed to the effects of anesthesia, “so it’s often left untreated when in reality we know not treating it increases morbidity and mortality,” he said.

More Systematic Assessment Needed

Dr. Raiten noted that not all ICUs have formal protocols for assessing delirium. He estimated that roughly half of cardiac ICUs at the University of Pennsylvania, for example, have formal assessments in place. Without such measures, however, delirium is often detected on morning rounds through discussions with the bedside nurses.

“A formal protocol to assess delirium in every patient should be standard practice in every ICU,” Dr. Raiten argued. “This is a global, unappreciated problem that’s inconsistently treated. We all treat the blood pressure when it’s low. We treat the heart when it’s not working. But it’s very easy to overlook the brain and not treat that when a patient just appears very withdrawn or mildly confused in bed, but they’re not causing harm to anybody or themselves.”

Delirium can be effectively treated through both nonpharmacological and pharmacological means, he pointed out. Nondrug methods are focused on reorienting patients to their location, the date, who they are, and their daily activities of living and on encouraging a normal sleep-wake cycle by keeping the lights on during the day and providing as much exposure to sunlight as possible. If that does not work, medical therapy centered on antipsychotics like haloperidol and quetiapine can be used.

“[Delirium is] relatively easy to treat when [addressed] promptly and a proper approach is taken, and it’s something we can really do to help our patients to decrease morbidity and mortality,” Dr. Raiten said.

Source:
Maniar H. Postoperative delirium increases both operative and one year mortality in patients treated with surgical or transcatheter aortic valve replacement. Presented at: American Association for Thoracic Surgery Annual Meeting; April 27, 2015; Seattle, WA.

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