Is Preoperative Functional Status Associated with Postoperative Mortality and Morbidity in Elective Open Heart Patients?

Heart disease, either coronary or valvular in nature, is typically a silent disease which progresses gradually over time. Cardiac surgery, even when planned, has the potential for adverse outcomes, such that several factors are taken into consideration to help surgeons and their patients discuss the potential risks weighed against the expected recovery. Physiological factors like body mass index and advanced age have more recently been accepted as additional cardiac surgery variables, but the impact of preoperative functional status on cardiac surgery, has not been adequately evaluated to date. This study aimed to examine the relationship between preoperative functional status and postoperative mortality and morbidity in elective open heart patients.

Preoperative baseline data (n = 43 subjects) were obtained to calculate Society of Thoracic Surgeons (STS) mortality and morbidity risk scores and preoperative functional status was measured using the Late-Life Function and Disability Instrument (LLFDI). Follow-up data were abstracted at one year postoperative to calculate actual mortality and morbidity events. Ordinary least squares and negative binomial regression analyses were conducted to assess the relationship between the LLFDI preoperative score to the STS mortality and morbidity risk scores. 

Mortality risk was significant, F (1, 39) = 4.75, p = 0.035, with an adjusted R2 = 0.086, and Function Total (measured by LLFDI) yielded a significant negative association with mortality risk, β = −0.329. Morbidity was found to be significant, F (1, 40) = 4.89, p = 0.033, with an adjusted R2 = 0.087 and Function Total yielded a significant negative association with morbidity risk, β = −0.328, as well. Estimation of the counts for postoperative complications as estimated by Function Total failed to reach significance (Wald χ2 = 0.34, p = 0.56), which provided a pseudo R2 = 0.009. Probabilities for frequencies of adverse events (major complications), therefore, could not be reliably calculated. 

In conclusion, preoperative diminished functional status, as measured by the Late-Life Function and Disability Instrument, is associated with an increased risk of mortality and morbidity in patients undergoing elective cardiac surgery. The risks and benefits of cardiac surgery should be weighed carefully and include a patient’s preoperative functional status, especially in the case of an elective procedure.

Article by A. Kate MacPhedran, et al, from USA.

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