Subjective assessment of functional capacity to predict postoperative myocardial injury and death: Hope or hype?

It is precisely the most subjective ideas which, being closest to nature and to the living being, deserve to be called the truest. Carl Gustav Jung Cardiac events are common after surgery and thus preoperative cardiac risk assessment is essential in all cases, even those who are apparently at low risk. The estimate of preoperative functional capacity is a tool for assessing cardiac risk, and a functional capacity of less than four metabolic equivalents of task is associated with an increased cardiac risk.1,2 The gold standard for determining functional capacity is the cardiopulmonary exercise stress test (CPET), which unfortunately is not widely used because it is time-consuming and expensive. Accordingly, in daily clinical practice the preoperative functional capacity is often estimated by the self-reported activity by the patient, clinical observations during the preoperative evaluation period or using questionnaires such as the Duke Activity Status Index questionnaire.3 In this issue of the journal, Marsman and colleagues report on 4879 patients; 824 (17%) had poor functional capacity by subjective assessment and 718 patients (15%) suffered from postoperative myocardial injury. Notably, poor functional capacity was associated with myocardial injury, postoperative myocardial infarction and one-year mortality. After adjusting for other predictors, functional capacity remained a significant predictor of myocardial injury, postoperative myocardial infarction and one-year mortality, but did not provide improved predictive value in addition to other predictors.4 Among the limitations of the study, troponin was not measured in 10% and functional capacity was not assessed in 7% of the patients. Nevertheless, these missing data probably occurred at random. Moreover, the CPET was not routinely performed, and thus it was not possible to determine whether the functional capacity estimated subjectively correlated well with the objective assessment. Finally, functional capacity assessment was not standardized, which may have influenced the results. Despite such drawbacks, this work expands the armamentarium of clinicians facing this complex task of risk prediction in the preoperative setting, which also includes focused frailty index, cardiac ultrasound, myocardial perfusion imaging, computed tomography and hybrid imaging.5,6,7,8–9 Indeed, recognizing the importance of eyeballing and apparently non-measurable estimates of risk and patient status brings us back to an era of more humanized medical practice, which could rest less on technology and thus exploit more physicians’ five senses, complemented by insight, acumen and empathy. Accordingly, in the modern era of personalized medicine encompassing clinical assessment with artificial intelligence and big data, it is reassuring to receive further proof of the importance of physician assessment and patient self-reported appraisal of health and disease.10 In conclusion, the article by Marsman and colleagues found that in patients undergoing non-cardiac surgery, subjective assessment of preoperative functional capacity can be a useful predictor of postoperative myocardial injury, infarction and death. Public health interventions to encourage the reduction of cardiac complications in postoperative surgery are necessary, and this novel piece of evidence reinforces the role of clinical judgement and involvement. The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The author(s) received no financial support for the research, authorship, and/or publication of this article. The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology.