A previous study at Indiana University demonstrated a reduction in myocardial infarction (MI) incidence with increased frequency of cardiac catheterization (CATH) in liver transplant (LT) candidates. A strict protocol for performing CATH based upon predefined risk factors, rather than non-invasive testing alone, was applied to a subgroup (2009-2010) from that study. CATH was followed by percutaneous coronary intervention (PCI) in cases of significant coronary artery disease (CAD; ≥50% stenosis). The current study applies this screening protocol to a larger cohort (2010-2016) to assess post-LT clinical outcomes.
Among 811 LT patients, 766 underwent stress testing (94%), and 559 underwent CATH (69%) of whom 10% had CAD requiring PCI. The sensitivity of stress echocardiography in detecting significant CAD was 37%. Predictors of PCI included increasing age, male gender and personal history of CAD (p<0.05 for all). Compared to patients who had no CATH, patients who underwent CATH had higher mortality (p=0.07), and the hazard rates (HR) for mortality increased with CAD severity [normal CATH (HR: 1.35 [95% CI: 0.79, 2.33], p=0.298); non-obstructive CAD (HR: 1.53 [95% CI: 0.84, 2.77], p=0.161); and significant CAD (HR: 1.96 [95% CI: 0.93, 4.15], p=0.080)]. Post-LT outcomes were compared to the 2009-2010 subgroup from the previous study and showed similar 1-year overall mortality (8% and 6%, p=0.48); 1-year MI incidence (<1% and <1%, p=0.8); and MI deaths as portion of all deaths (3% and 9%, p=0.35).
Stress echocardiography alone is not reliable in screening LT patients for CAD. Aggressive CAD screening with CATH is associated with low rate of MI and cardiac mortality and validates the previously published protocol when extrapolated over a larger sample and longer follow-up period.