In patients who have had a previous CABG, myocardial perfusion predicts poor outcomes.
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| Image: Human Heart 3D Image | InStyleHealth |
According to the results of a study, global stress
myocardial blood flow (MBF) and perfusion reserve (MPR) generated from
perfusion mapping cardiac magnetic resonance (CMR) are independently predictive
of bad outcomes in patients who have had a prior coronary artery bypass graft
(CABG).
The existence of regional ischemia on visual
assessment and the amount of previous infarction have no effect on this effect,
according to the authors.
This retrospective study looked at whether global
stress MBF and MPR independently predicted bad outcomes in patients who had
previously undergone CABG and were referred for adenosine stress perfusion CMR.
The authors used automated MBF quantification to do perfusion mapping.
The primary outcome was a composite of all-cause
mortality and major adverse cardiovascular events, which were defined as
nonfatal myocardial infarction and unscheduled revascularization. Cox
proportional hazards models were used to examine relationships, which were
adjusted for comorbidities and CMR characteristics.
The study comprised 341 patients (median age 67 years,
86 percent male), with 81 (24 percent) achieving the primary result after a
median follow-up of 638 days (interquartile range 367976).
Stress BMF and MPR independently predicted outcomes
after controlling for established prognostic variables (i.e., regional ischemia
and infarction). The adjusted hazard ratios for 1 mL/g/min drop in stress MBF
were 2.56 (95 percent confidence interval [CI], 1.454.35) and 1.61 (95 percent
confidence interval [CI], 1.082.38) for 1 unit decrease in MPR.
"Patients who have had previous CABG surgery
often have complicated coronary disease and are still at a significant risk of
adverse outcomes," the researchers wrote. "In native vascular
disease, quantitative myocardial perfusion measures predict outcomes."