Impact of Nonobstructive Left Main Coronary Artery Atherosclerosis on Long-Term Mortality
Masahiko Noguchi1, Fotios Gkargkoulas2, Mitsuaki Matsumura3
1Clinical Trials Center, Cardiovascular Research Foundation, New York, New York, USA; NewYork-Presbyterian Hospital/Columbia University Medical Center, New York, New York, USA; Department of Cardiology, Tokyo Bay Urayasu Ichikawa Medical Center, Urayasu, Japan.
Insights
Increased left main coronary artery plaque burden, even without severe stenosis, is linked to higher long-term mortality. This finding highlights the importance of assessing plaque burden for predicting cardiac death risk.
Area of Science:
- Cardiology
- Vascular Imaging
- Outcomes Research
Background:
- Severe left main coronary artery (LMCA) stenosis predicts mortality.
- The prognostic impact of nonobstructive LMCA atherosclerosis remains unclear.
Purpose of the Study:
- To investigate the association between LMCA disease, assessed by intravascular ultrasound (IVUS), and long-term mortality.
- To determine if LMCA plaque burden predicts mortality independently of lumen area.
Main Methods:
- A cohort of 3,239 patients with LMCA IVUS imaging and no prior or planned revascularization was analyzed.
- Long-term all-cause and cardiac mortality were assessed up to 12 years using the National Death Index.
- Intravascular ultrasound (IVUS) measured LMCA minimum lumen area (MLA) and plaque burden.
Main Results:
- The median follow-up was 8.2 years, with 12-year all-cause and cardiac death rates of 37.5% and 17.0%, respectively.
- Higher LMCA plaque burden was significantly associated with increased all-cause and cardiac mortality (adjusted HR per 10%: 1.12).
- LMCA minimum lumen area (MLA) was not independently associated with long-term mortality after adjustment.
Conclusions:
- Increasing LMCA plaque burden is an independent predictor of long-term all-cause and cardiac mortality.
- These risks persist even in the absence of obstructive LMCA stenosis.
- IVUS assessment of plaque burden is crucial for risk stratification in patients with LMCA disease.
Background:
Although the presence of severe stenosis in the left main coronary artery (LMCA) is a well-established predictor of mortality, whether this extends to nonobstructive atherosclerosis in the LMCA is unknown.
Objectives:
The aim of this study was to evaluate the association between LMCA disease by intravascular ultrasound (IVUS) and long-term mortality.
Methods:
Between 2005 and 2013, 3,239 patients with LMCA IVUS imaging without LMCA revascularization (either before angiography or scheduled based on index angiography or IVUS) were included. The primary and secondary endpoints were all-cause and cardiac mortality at a minimum of 5 years obtained from the National Death Index.
Results:
The IVUS-measured LMCA minimum lumen area (MLA) and plaque burden were 13.1 ± 5.0 mm2 and 41.7% ± 15.6%, respectively. The median follow-up was 8.2 years. The Kaplan-Meier estimated 12-year all-cause and cardiac death rates were 37.5% and 17.0%, respectively. Greater plaque burden (unadjusted HR per 10%: 1.17; 95% CI: 1.12-1.22; P < 0.0001) and smaller IVUS MLA (unadjusted HR per 1 mm2: 0.98; 95% CI: 0.96-0.99; P = 0.0008) were associated with all-cause death. After adjusting for clinical, angiographic, and IVUS factors, plaque burden (adjusted HR per 10%: 1.12; 95% CI: 1.04-1.21; P = 0.003) but not MLA (adjusted HR per 1 mm2: 1.02; 95% CI: 0.99-1.04; P = 0.18) was associated with long-term all-cause death. These findings were also consistent for long-term cardiac mortality.
Conclusions:
In the present large-scale study with a 12-year follow-up, increasing LMCA plaque burden was associated with long-term all-cause and cardiac mortality in patients not undergoing LMCA revascularization, even when the lumen area was preserved.
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