Multivessel coronary disease (MVD) is common in NSTEMI patients but most patients receive only single vessel PCI, Australian research shows.
A study of 3,722 consecutive NSTEMI presentations to three tertiary hospitals in Adelaide between 2012 and 2016 found 42% had MVD – 21% with two affected vessels and 21% with three affected vessels.
It found age, male gender, diabetes, dyslipidaemia and prior MI all independently predicted MVD over and above having single vessel or no significant coronary artery stenosis.
The study, published in Cardiovascular Diagnosis & Therapy, found PCI was performed in 42% of patients, including in 61% of patients with two-vessel disease and 22% of three-vessel disease.
“Of the 649 patients with MVD who underwent PCI, 491 (76%) received single-vessel PCI alone,” it said.
In patients with two-vessel disease receiving PCI, 81% had single-vessel PCI and 19% had the intervention in both vessels.
“In patients with 3-VD receiving PCI, 103 patients (62%) had single-vessel PCI, 45 (27%) had two-vessel PCI and only 19 (11%) had PCI to all three coronary artery territories.”
The study found in-hospital mortality was 0.9% overall, increasing with the number of diseased vessels (0.3% for 0-VD, 0.5% for 1-VD, 1.3% for 2-VD and 2.0% for 3-VD, P=0.002).
“Although underpowered to determine the effect of MVD on clinical outcomes, our data suggest that it is associated with higher inpatient mortality, a finding well established with respect to all acute coronary syndromes,” the study said.
The researchers, led by Dr Angus Baumann, said their data was collected before the 2019 COMPLETE trial showed benefit for multi-vessel PCI in the STEMI population.
This may in turn have influenced practice in the NSTEMI cohort, they said.
“As the question of whether multivessel PCI confers superior outcomes in these patients remains largely unanswered, future prospective trials are needed to investigate optimal revascularisation strategies,” they concluded.
Dr Baumann, now a cardiologist at Alice Springs Hospital, told the limbic the heterogeneity of underlying pathologies in NSTEMI created a challenge.
“I think what came out of this paper we’ve just published and also a  review we did is that a big problem with the NSTEMI is it’s almost a catch all for ACS with a troponin rise that isn’t STEMI.”
“STEMI is 95% of the time atherosclerotic plaque rupture, occluded vessels, and they get treated but NSTEMI is just so many different underlying pathologies so any kind of prospective study would be a challenge.”
“There are probably 5 or 6 groups within the NSTEMI cohort that you want to treat a little bit differently.”
Dr Baumann added that the fact that 76% of patients with NSTEMI and MVD received culprit lesion-only PCI reflected caution.
“I think probably part of that is the old practice of not doing the non-culprit lesions and we haven’t shown it applies benefit to NSTEMI.”
“The fact is that for a long time, even in STEMI, the practice was not to do it [complete revascularization] because there was data that there was no benefit and potential harm.”
He said any stenting procedure involved risk such as early stent thrombosis, vessel dissection, contrast leading to renal impairment, and stroke.
“This risk is inherent every single time you do these procedures but the longer you go and the more complex, the more those risks actually add up.”
“You want to hope you’re getting benefit from putting the stent in and for a long time in STEMI we didn’t think we did. And we just don’t know what is going to happen to those non-culprit vessels in NSTEMI.”
“In STEMI, it’s a big inflammatory process and therefore you think those non-culprit lesions might be more likely to rupture and break up and cause an event in the future.”
“In NSTEMI… they don’t necessarily have the big inflammatory process at the time of their NSTEMI. You don’t necessarily know that the risk from the non-culprits is that high.”