Percutaneous coronary intervention (PCI) for unprotected left main coronary artery
(ULMCA) disease has emerged as a viable alternative to coronary artery bypass graft
(CABG) surgery in specific patterns of coronary involvement. Recent evidence suggests it
is best utilised in patients with limited overall coronary disease burden and complexity,
yet in current practice it is often employed for those with high surgical risk. While there
are published data on outcomes following ULMCA PCI is selected groups of patients,
there are limited data describing current real-world practice. Current revascularisation
guidelines apply data from randomised studies using traditional outcome measures to
stratify the appropriate use of treatment modalities. Although measures of health-related
quality of life (HRQOL) are recognised to be important to patients, they are rarely taken
into consideration in contemporary guidelines or clinical decision making. While there is
limited knowledge surrounding the HRQOL outcomes from randomised studies of LMCA
revascularisation, no published studies have assessed HRQOL outcomes in the ‘real world’
population treated for LMCA disease, including those who are medically managed.
Methods:
First, we undertook a retrospective analysis of patients undergoing PCI for ULMCA at a
single cardiac centre in the UK. We identified a retrospective cohort of patients who
received LMCA PCI between March 2005 and March 2013. We applied Cox proportional
hazards model to identify the major predictors of poor survival and clinical outcomes. The
primary composite outcome was major adverse cardiac and cerebrovascular events
(MACCE), comprising all-cause mortality, myocardial infarction, stroke and repeat
revascularisation. In separate analyses, we excluded patients with cardiogenic shock,
while other subgroups analysed included LMCA bifurcation cohorts and octogenarians.
Second, we recruited a prospective cohort of patients with LMCA disease managed
conservatively or by PCI or CABG and applied an HRQOL questionnaire at 4 times points
over the course of 1 year follow-up. Multilevel modelling using linear mixed models was
used to conduct longitudinal analyses of HRQOL outcomes.
Results:
The Kaplan-Meier estimate of MACCE at 1 year was 26.2% and at the median (IQR)
follow-up of 584 (1036) days it was 41.8%. Significant factors associated with MACCE
include SYNTAX score(SS) [ Hazard ratio (HR) 1.01; 95% Confidence Interval (CI): 1.00 -
1.02; p<0.05], presentation in cardiogenic shock [adjusted Hazard Ratio (aHR) 5.88, 95%
CI 3.81-9.06, p<0.05], previous MI [aHR 1.94, 95% CI 1.37-2.75, p<0.05] and a history of
diabetes [aHR 1.61, 95% CI 1.12-2.31, p<0.05] after long term follow-up. With a separate
analysis excluding patients with cardiogenic shock we found SS [aHR 1.02, 95% CI 1.00-
1.04, p<0.05], previous MI [aHR 1.89, 95% CI 1.28-2.80, p<0.05], peripheral vascular
disease [aHR 1.68, 95% CI 1.09-2.61, p<0.05] and renal impairment [aHR 1.89, 95% CI
1.05-3.43, p<0.05] were significantly associated with MACCE; for every 10 unit increase in
SS there was a 2% increase in the risk of MACCE. In a separate analysis of patients with
‘True’ LMCA bifurcation disease, there was no difference in survival from a single or two
stent strategy. Residual coronary disease amongst octogenarians was assessed using the
residual SS, each 10 unit increase in rSS was associated with a 3% increase in all-cause
mortality (aHR 1.03; 95% CI, 1.00-1.06; p=0.04]. HRQOL was found to deteriorate
significantly over 1 year for patients managed conservatively, while despite earlier
improvement in HRQOL following PCI, the HRQOL for patients treated with CABG
overtook these and showed greater and more sustained improvement over 1 year.
Conclusion:
This database describes a real world cohort of patients with LMCA, with significantly
greater coronary disease burden and comorbidity than most published studies. While
cardiogenic shock was a strong predictor of poor outcomes, the SS was also associated
with poor outcomes. Other measures of coronary disease burden, such as ‘True’
bifurcation disease are significant predictors of poor outcomes. Diabetes is a predictor of
outcome, yet after excluding cardiogenic shock, the association is no longer evident. After
adjusting for the sequelae of the diabetes, such as renal impairment and burden of
atheromatous disease (SS and PVD), these variables become significant predictors of
poor outcomes.. Residual SS following PCI was associated with poor outcomes in this
long-lived population, suggesting that untreated coronary disease is undesirable, although it is not clear that more aggressive revascularisation is indicated. HRQOL
measures suggest that, despite selection bias, patients currently selected for conservative
management for LMCA may benefit from some form of targeted revascularisation despite
limited prognostic benefit.
