Trends in Clinical Practice and Outcomes After Percutaneous Coronary Intervention of Unprotected Left Main Coronary Artery

Abstract

Background The use of percutaneous coronary intervention (PCI) to treat unprotected left main coronary artery disease has expanded rapidly in the past decade. We aimed to describe nationwide trends in clinical practice and outcomes after PCI for left main coronary artery disease. Methods and Results Patients (n=4085) enrolled in the SCAAR (Swedish Coronary Angiography and Angioplasty Registry) as undergoing PCI for left main coronary artery disease from 2005 to 2017 were included. A count regression model was used to analyze time-related differences in procedural characteristics. The 3-year major adverse cardiovascular and cerebrovascular event rate defined as death, myocardial infarction, stroke, and repeat revascularization was calculated with the Kaplan-Meier estimator and Cox proportional hazard model. The number of annual PCI procedures grew from 121 in 2005 to 589 in 2017 (389%). The increase was greater for men (479%) and individuals with diabetes (500%). Periprocedural complications occurred in 7.9%, decreasing from 10% to 6% during the study period. A major adverse cardiovascular and cerebrovascular event occurred in 35.7% of patients, falling from 45.6% to 23.9% (hazard ratio, 0.56; 95% CI, 0.41-0.78; P=0.001). Radial artery access rose from 21.5% to 74.2% and intracoronary diagnostic procedures from 14.0% to 53.3%. Use of bare-metal stents and first-generation drug-eluting stents fell from 19.0% and 71.9%, respectively, to 0, with use of new-generation drug-eluting stents increasing to 95.2%. Conclusions Recent changes in clinical practice relating to PCI for left main coronary artery disease are characterized by a 4-fold rise in procedures conducted, increased use of evidence-based adjunctive treatment strategies, intracoronary diagnostics, newer stents, and more favorable outcomes.

Keywords: PCI; unprotected left main coronary artery disease.

Figure 1. Temporal trends in demographics, clinical presentation, and treatment in patients with LMCA treated with PCI.

Temporal trends in PCI‐treated unprotected left main coronary artery disease by (A) patient characteristics; (B) clinical presentation; (C) multidisciplinary heart team decision; (D) periprocedural treatment; (E) PCI techniques and anatomic/physiological diagnostic procedures; and (F) stent details. All panels but panel C show absolute number of patients per year. Figure 1C shows the proportion of patients declined from CABG and those that were not declined but in whom PCI was preferred by number of patients discussed at a multidisciplinary heart team meeting, whereas the proportion of patients undergoing ad hoc PCI is presented as a proportion of all PCI‐LMCA. BMS indicates bare‐metal stent; CCS, chronic coronary syndrome; DES, drug‐eluting stent; DM, diabetes mellitus; FFR/iFR, fractional flow reserve/instant wave‐free ratio; GPIIB/IIA, glycoprotein IIB/IIA; IVUS, intravascular ultrasonography; NSTE‐ACS, non–ST‐segment–elevation acute coronary syndrome; OCT, optical coherence tomography; PCI‐LMCA, percutaneous coronary intervention for unprotected left main coronary artery disease; and STE‐ACS, ST‐segment–elevation acute coronary syndrome.

Figure 2. Anatomic pattern of LMCA lesions treated with PCI.

(A) Proportion of anatomic locations of coronary artery lesions of the studied cohort and (B) their classifications according to American College of Cardiology/American Heart Association. Cx indicates circumflex artery; LAD, left anterior descending artery; LM, left main; LMCA indicates left main coronary artery disease; and PCI, percutaneous coronary intervention.

Figure 3. Periprocedural complications in PCI‐LMCA.

A, Frequency of periprocedural complications. B, Temporal trends in periprocedural complications as 2‐year running average. CABG indicates coronary artery bypass grafting; PCI‐LMCA, percutaneous coronary intervention for unprotected left main coronary artery disease.

Figure 4. Kaplan‐Meier failure estimates of primary end point of PCI‐LMCA.

A, Cumulative incidence and Kaplan‐Meier event rates of the primary outcome of MACCE within 3 years defined as the first occurrence of all‐cause death, repeat revascularization (target lesion revascularization or CABG), stroke, or new myocardial infarction. B through F, Cumulative incidence of MACCE according to sex, age group, diabetes status, clinical presentation, and stent type. BMS indicates bare‐metal stent; CABG, coronary artery bypass grafting; CCS, chronic coronary syndrome; DES, drug‐eluting stent; MACCE, major adverse cardiovascular and cerebrovascular event; NSTE‐ACS, non–ST‐segment–elevation acute coronary syndrome; PCI‐LMCA, percutaneous coronary intervention for unprotected left main coronary artery disease; and STE‐ACS, ST‐segment–elevation acute coronary syndrome.

Figure 5. Temporal trends in long‐term outcome of PCI‐LMCA.

A, Three‐year risk of primary and secondary outcomes as 2‐year running average of the Kaplan‐Meier estimates. B, Three‐year risk of MACCE over time as 2‐year running average of the Kaplan‐Meier estimates. C, Three‐year Kaplan‐Meier event rates of the primary outcome together with hazard ratio and 95% CI by year. CCS indicates chronic coronary syndrome; DM, diabetes mellitus; MACCE, major adverse cardiovascular and cerebrovascular event; NSTE‐ACS, non–ST‐segment–elevation acute coronary syndrome; STE‐ACS, ST‐segment–elevation acute coronary syndrome; and TLR, target lesion revascularization.

Figure 6. Landmark analysis of MACCE at 30 days after PCI‐LMCA.

Cumulative incidence and Kaplan‐Meier event rates of the primary outcome major adverse cardiovascular and cerebrovascular event (MACCE) within and after 30 days. PCI‐LMCA indicates percutaneous coronary intervention for unprotected left main coronary artery disease.

Figure 7. Outcome according to American Heart Association (AHA) lesion complexity.

Lesions classified as C or C bifurcation according to the American Heart Association lesion classification were associated with highest incidence of MACCE within 3 years. MACCE indicates major adverse cardiovascular and cerebrovascular event.