Residual Inflammatory Risk in Patients With Low LDL Cholesterol Levels Undergoing Percutaneous Coronary Intervention

Background: Data on the impact of residual inflammatory risk (RIR) in patients undergoing percutaneous coronary intervention (PCI) with baseline low-density lipoprotein cholesterol (LDL-C) ≤70 mg/dl are scarce.

Objectives: The purpose of this study was to characterize the prevalence and impact of persistent high RIR after PCI in patients with baseline LDL-C ≤70 mg/dl.

Methods: All patients undergoing PCI between January 2009 and December 2016 in a single tertiary center, with baseline LDL-C ≤70 mg/dl and serial high-sensitivity C-reactive protein (hsCRP) assessments (at least 2 measurements ≥4 weeks apart) were retrospectively analyzed. High RIR was defined as hsCRP >2 mg/l. Patients were categorized as persistent low RIR (first low then low hsCRP), attenuated RIR (first high then low hsCRP), increased RIR (first low then high hsCRP), or persistent high RIR (first high then high hsCRP). Primary endpoint of interest was major adverse cardiac and cerebrovascular accident (MACCE) (death, myocardial infarction, or stroke), within 1 year of the second hsCRP measurement.

Results: A total of 3,013 patients were included, with persistent low, attenuated, increased, and persistent high RIR in 1,225 (41.7%), 414 (13.7%), 346 (11.5%), and 1,028 (34.1%) patients, respectively. Overall, there was a stepwise increase in the incidence rates of MACCE, transitioning from the persistent low to the attenuated, increased, and persistent high RIR (respectively, 64.4 vs. 96.6 vs. 138.0 vs. 152.4 per 1,000 patient-years; p < 0.001). After adjustment, the presence of persistent high RIR remained strongly associated with MACCE (adjusted hazard ratio: 2.10; 95% confidence interval: 1.45 to 3.02; p < 0.001).

Conclusions: Among patients undergoing PCI with baseline LDL-C ≤70 mg/dl, persistent high RIR is frequent and is associated with increased risk of MACCE. Targeting residual inflammation in patients with optimal LDL-C control may further improve outcomes after PCI.