Cardiopulmonary Bypass Reduces COVID-19 Vaccine Antibody Levels Short-Term

In the short-term following cardiopulmonary bypass (CPB), COVID-19 vaccine antibody concentrations are significantly reduced, but within 1 month return to pre-CPB levels, according to study findings published in the Journal of the American Heart Association.

With virtually no literature describing the effects of CPB on adult patients recently immunized against COVID-19, investigators aimed to assess how COVID-19 vaccination antibody concentrations might be affected by CPB in cardiac procedures.

They conducted a prospective observational monocentric clinical trial that included 77 adult participants aged older than 18 years who received a cardiac procedure requiring CPB between September 2021 and July 2022. All participants had received at least 1 dose of a COVID-19 vaccination series (complete vaccination series) prior to receiving their procedures. A pre-CPB measurement was taken of SARS-CoV-2 spike protein-specific antibody concentrations, and the measurement was repeated 24 hours following CPB (postoperative day 1) and again at 1 month following CPB.

Among the participants (median age, 67 [IQR, 61-70] years; 27.3% women; 89.6% White), 48.1% had hypertension, 44.2% were obese, 22.1% had diabetes, 10.4% were immunosuppressed, 2.6% were on dialysis before surgery, and 27.3% were current smokers. The majority of patients (50.6%) received the Pfizer-BioNTech vaccine, and 52.6% of all patients received a booster dose before surgery. Median time from last vaccine to surgery was 157 days (IQR, 46-221), and 18.2% of patients had prior history of COVID-19 infection.

Operative mortality occurred in 4 participants.

On postoperative day 1 (POD1), the investigators found mean antibody concentration significantly decreased relative to pre-CPB levels (-2091 AU/mL; P <.001). Subsequently, at the 1-month post-CPB measurement relative to the POD1 measurement, antibody concentration increased (2465 AU/mL; P =.015). The investigators found no significant difference between pre-CPB and the 1-month post-CPB concentrations (P =.983).

Postoperatively, 2 participants developed symptomatic COVID-19 pneumonia of which 1 case resulted in mortality. COVID-19 pneumonia diagnosis required a positive polymerase chain reaction test in addition to clinical and imaging findings consistent with viral pneumonia.

Diabetes was significantly associated with an increase in antibody concentration between pre-CPB and POD1 (2107 AU/mL; P =.040). However, no patient-reported characteristics were found to be significantly associated with changes in antibody concentration after applying the Hochberg sequential procedure for multiple comparisons.

Study limitations include the underpowered sample size and the lack of additional antibody measurements between the 24-hour post CPB and the 1-month post-CPB.

“COVID-19 vaccine antibody concentrations were significantly reduced in the short-term following CPB but returned to pre-CPB levels within 1 month,” the investigators wrote. “These findings suggest the need for heightened precautions in the perioperative period for cardiac surgery patients.”