Effects of statin and antiplatelet therapy noncompliance and intolerance on patient outcomes following vascular surgery

Abstract

Objective: Prior studies have evaluated the effects of statin and antiplatelet agent (APA) medications on patients with peripheral arterial disease. Although the benefits of statin and APA use are well-described, there is a paucity of research into the specific outcomes of patients who are not compliant or those who are unable to take the medication owing to intolerance. Here we examine the outcomes of patients intolerant to statin and APA and compare them with patients who are compliant or noncompliant with these therapies.

Methods: Patients treated from 2005 to 2018 in the Vascular Quality Initiative registry were included. Patients with missing data or deaths within 30 days of procedure were removed. Patients were considered noncompliant if they were previously prescribed a medication at discharge but were not taking it at 1-year follow-up or if the patient was reported to be noncompliant in the registry. Medication intolerance was defined if listed as "no, for medical reasons," and mortality data were ascertained using the Social Security Death Index, which is regularly cross-referenced to the Vascular Quality Initiative registry.

Results: We identified 105,628 patients who met our inclusion criteria. Statin intolerance was noted in 2.3% at discharge and 2.1% at the 1-year follow-up, with 0.7% listed as intolerant at all stages. Factors associated with increased risk of intolerance to statins included female gender (P = .001), discharge APA intolerance (P = .004), insurance status (non-U.S. insurance) (P < .001), discharge APA noncompliance (P = .019), and discharge angiotensin converting enzyme inhibitor noncompliance (P = .005). Patients who were compliant with statins showed a 91% survival at 5 years vs 87% survival in noncompliant patients and 87% in intolerant patients at 5 years (P < .001). Patients with statin intolerance have a similar survival curve as noncompliant patients across all registry cohorts. Noncompliance with statins was correlated with noncompliance with APA medications (R = 0.16, P < .001). Factors associated with increased risk of statin noncompliance included preoperative ambulatory status (requiring assistance) (P = .039), female sex (P < .001), peripheral vascular intervention (P < .001) or infrainguinal open bypass procedure surgery (P = .001), discharge status (to nursing home) (P = .006) and insurance (self-pay) (P < .001).

Conclusions: Patients not taking statin and APA medications have a substantially decreased 5-year survival irrespective of the reason for not taking. Importantly, patients noted to be intolerant have a similar survival curve as noncompliant patients across all registry cohorts. Intolerant patients may benefit from attempts to alter statin dose, type (hydrophilic vs lipophilic), or from newer agents such as PCSK9 inhibitors.

Keywords: Antiplatelet; Arterial; Atherosclerosis; Intolerance; Peripheral; Statin.