What Is the Appropriate Pre-procedural Evaluation of Patients With Vascular Disorders?

Welcome to the August 2020 edition of Vascular Disease Management. Although this issue has multiple submissions worthy of editorial discussion, I have chosen to comment on Dr. Sherif Sultan and colleagues’ article “Predictive Utility of Preoperative NT-proBNP Levels in Cardiovascular Outcomes of Abdominal Aortic Aneurysm Repair” in which he noted that patients with elevated serum pre-procedural levels of NT-proBNP experienced higher morbidity and mortality following open and endovascular repair of abdominal aortic aneurysms. 

NT-proBNP (N-terminal prohormone of Brain Natriuretic Peptide) is an inactive 76-amino acid prohormone that is cleaved to create the active BNP (Brain Natriuretic Peptide). NT-proBNP and BNP are released primarily from left ventricular myocardium in response to myocyte stretch from pressure overload or ventricular dilatation.  NT-proBNP and BNP levels typically rise together but NT-proBNP levels are typically more stable in the blood therefore health care providers often use these values to clinically follow patients with suspected heart failure.

The findings in this study suggest that individuals with underlying myocardial dysfunction fare worse than those with normal myocardial function. 

Atherosclerotic peripheral arterial disease and abdominal aortic aneurysmal disease have a strong association with coronary arterial disease. The overwhelming cause of death in individuals presenting with these disorders are heart related. It therefore makes sense that those with evidence of myocardial dysfunction or advanced coronary artery disease should be identified a priori not only to stratify procedural risk but also to ensure appropriate long-term survival with continued therapy aimed at overall risk reduction of subsequent cardiac events. Atherosclerosis is a systemic disease that may affect certain arteries more than others or may affect multiple vascular beds. Most studies evaluating the efficacy of preoperative evaluation of patients with vascular disorders concentrate on the value of these evaluations in decreasing procedural risk. Although I believe that this is an important issue it is much less important than long-term survival and the avoidance of adverse cardiac outcomes associated with increased morbidity and mortality. There can be no argument that patients with advanced vascular disorders should have hypertension, hyperlipidemia, and glycemic control. These patients should quit smoking. These patients should have some measurement of heart function (and echocardiography, BNP and NT-proBNP may be measures of heart function) and some evaluation of myocardial ischemia (which can be ascertained via cardiac nuclear studies, cardiac PET scans, or CT-FFR) to determine if there is underlying significant myocardial ischemia. Standard treadmill tests are often suboptimal as many patients are unable to achieve target heart rates secondary to physical deconditioning or claudication and false negative studies are common.

Longitudinal follow-up must be established not only to assess the results of the intervention but also to supervise adequacy of risk factor modification and to evaluate for evidence of progressive disease processes that may result in increased morbidity and mortality. Physical completion of a surgical or non-surgical intervention is not the end of the patient’s treatment.