OA1-AM24-SN-15 - Abnormal Pre-Donation Blood Pressure And Adverse Events In Whole Blood And Apheresis Donation

The measurement of pre-donation blood pressure (BP)  is one of the many strategies to prevent adverse events in whole blood and apheresis donors. However, few data support this practice, even though it has been in effect for a long time in many blood services. This study assessed the impact of abnormal BP on the risk of vasovagal reaction (VVR) and cardiovascular complications among blood donors. Understanding this association is crucial given its potential implications for donor safety and blood donation procedures.

Study

Design/Methods:

Pre-donation BP was measured in all donors (i.e., whole blood, apheresis, and platelet donors) throughout a North American jurisdiction over an 18-month period (i.e., “study period”, from June 2022 to December 2023). An abnormally low BP was defined as a systolic BP < 90 mmHg and/or a diastolic BP < 50 mmHg. An abnormally high BP was defined as a systolic BP >180 mmHg and/or a diastolic BP >100 mmHg. During the study period, donors with abnormal BP were not deferred.

The association of abnormal BP with VVRs (primary outcome) and cardiovascular complications (secondary outcome) was evaluated using stratified analyses and logistic regressions, adjusting for age, sex, type of donation (i.e., whole blood, plasma, platelets), and donor status (i.e., first-time or active repeat donor). Odds ratios (OR) with corresponding 95% confidence intervals (CI) were reported.

Results/Findings:

The study included 596,135 donations, including 257,500 (43.2%) from female donors, 51,437 (8.6%) from first-time donors, and 347,787 (62.9%) from whole blood donors. Overall, 523,996 (98.5%) donations were from donors with a normal BP, 530 (0.1%) were from donors with an abnormally low BP, and 7516 (1.4%) were from donors with an abnormally high BP; 15,869 VVRs were observed.

Using logistic regression, there was no statistically significant association between the risk of VVR and an abnormally low (OR [95% CI] =1.03 [0.67–1.61]) or high BP (OR [95% CI]=0.96 [0.81–1.14]) versus a normal BP. Table 1 shows the association between BP and VVR within each category of other covariates in the multivariate regression model. In particular, there was no association between BP and VVR within each level of severity of VVR. Only one frequent donor with a normal pre-donation BP experienced a cardiovascular complication.

Conclusions:

This study suggests that abnormal BP measurements are not associated with an elevated risk of VVR, neither overall nor in subgroups based on sex, age, type of donation, donor status, or VVR severity. These findings do not support the relevance of measuring BP for the prevention of VVRs and cardiovascular complications among blood donors.