PRESC1SE-MI and meta-analysis

How do the 0/1-hour and 0/3-hour pathways compare?

The 0/1-hour pathway was developed to speed up the diagnosis of MI compared to measurements of troponin 3 hours apart. Subsequent results from prospective studies led to the 0/1-hour pathway being recommended in ESC Clinical Practice Guidelines [1]. However, as noted by presenter of the PRESC1SE-MI trial, Professor Christian Mueller (University Hospital Basel - Basel, Switzerland), uncertainty remained regarding the safety and efficacy of the 0/1-hour pathway, which led to many hospitals not adopting the new approach. “We conducted the PRESC1SE-MI trial to determine whether implementation of the 0/1-hour pathway, as compared to the 0/3-hour pathway, provided similar safety while reducing ED length of stay across diverse healthcare systems,” he said.

PRESC1SE-MI was a stepped-wedge, cluster-randomised trial conducted at 20 hospitals in 11 countries. In total, 67,624 consecutive patient presentations to the ED with suspected MI were analysed.

The researchers found that the occurrence of the co-primary safety outcome of all-cause death or new type 1 MI within 30 days with the 0/1-hour pathway was noninferior to the 0/3-hour pathway (1.1% and 1.2%, respectively; adjusted odds ratio [OR] 0.93; 95% CI 0.77 to 1.13; p value for noninferiority <0.001). However, they also noted that the co-primary efficacy outcome – the length of stay in the ED – was not reduced with the 0/1-hour pathway. The median ED length of stay was 309 minutes in both groups (p=0.65).

In the next presentation, Professor Jasper Boeddinghaus (University Hospital Basel - Basel, Switzerland) described a meta-analysis of individual participant data from the PRESC1SE-MI trial and other randomised trials that evaluated the 0/1-hour pathway vs. standard pathways. Across 5 trials and 110,933 patient presentations, implementation of the 0/1-hour pathway was associated with low rates of all-cause death or new type 1 MI within 30 days, but the pooled safety estimate remained imprecise. Earlier cardiac troponin retesting did not reduce average ED length of stay or increase direct discharge.

Summing up the results overall, Prof. Boeddinghaus said: “These findings are important to healthcare providers worldwide as they contradict current assumptions that implementing 0/1-hour testing improves patient management in the ED. It seems that other processes – including specialist review, admissions workflow and bed availability – may have a greater influence on ED length of stay than the testing strategy alone. Approaches such as integrating the 0/1-hour pathway into electronic healthcare records as a clinical decision-support tool may be beneficial to bring the benefits of rapid testing to patients and the healthcare system as a whole.”

AIR-STEMI

Is functional coronary angiography beneficial in patients with STEMI and multivessel CAD?

As presented by Associate Professor Simone Biscaglia (University Hospital of Ferrara - Ferrara, Italy), the AIR-STEMI trial evaluated complete revascularisation guided by functional coronary angiography vs. conventional angiography-guided complete revascularisation in patients with STEMI and multivessel CAD.

AIR-STEMI was an investigator-initiated trial conducted in 21 centres in Italy and Pakistan, which included patients with STEMI and multivessel disease who had undergone successful PCI for the culprit lesion. In total, 1,823 patients were randomised to complete revascularisation guided by functional coronary angiography or by conventional angiography. In the functional coronary angiography group, all qualifying non-culprit lesions were assessed using angiography-derived fractional flow reserve (FFR). Lesions with an FFR value more than 0.80 were deferred, whereas lesions with an FFR value less than or equal to 0.80 were treated with PCI. FFR analyses were centralised in the core lab. When PCI was indicated, the functional coronary angiography assessment was used to plan treatment by identifying the segment responsible for the greatest physiological impairment. In the angiography-guided group, PCI was recommended for all non-culprit lesions with stenosis of at least 50% estimated by conventional angiography.

In the functional coronary angiography group, 51.9% of non-culprit lesions underwent PCI compared with 94.9% of non-culprit vessels in the angiography-guided group. This translated into fewer procedures, fewer treated vessels, shorter treated segments and lower use of contrast agents with the physiology-guided strategy.

At a median follow-up of 17.9 months, the primary endpoint of all-cause death, MI, cerebrovascular accident or ischaemia-driven coronary revascularisation was significantly reduced in the functional coronary angiography group compared with the angiography-guided group (8.9% vs.13.7%; hazard ratio [HR] 0.62; 95% CI 0.47 to 0.83; p<0.001).

Both procedure-related and spontaneous MI and revascularisation were significantly reduced with functional coronary angiography. There was no significant difference for all-cause mortality (3.9% vs. 5.1%; HR 0.77; 95% CI 0.50 to 1.20).

The main safety endpoint of contrast-associated acute kidney injury or major bleeding occurred less frequently in the functional coronary angiography group than the angiography-guided group (4.6% vs. 7.1%; HR 0.63; 95% CI 0.43 to 0.93; p=0.02).

Associate Prof. Biscaglia concluded: “Functional coronary angiography allowed us to select and treat only those non-culprit lesions that were clinically important, reducing unnecessary procedures and the risk of complications. By moving beyond visual estimation alone, this approach brings complete revascularisation closer to precision medicine: treating the lesions that matter, while avoiding unnecessary PCI in lesions that do not appear to limit blood flow. These results support functional coronary angiography as a new strategy to make complete revascularisation more selective, safer and more personalised in this high-risk population.”

TARGET-CTCA

Do patients with acute chest pain and intermediate-risk hs-cTn levels benefit from CCTA after discharge?

The majority of patients with suspected ACS presenting to the ED will be discharged once MI has been ruled out, although a proportion will have unrecognised CAD. As described by Professor Nicholas Mills (University of Edinburgh - Edinburgh, UK), the TARGET-CTCA trial investigated whether outpatient CTCA could reduce subsequent MI or cardiac death in patients with intermediate hs-cTn concentrations.

In total, 3,170 patients with suspected ACS were enrolled in the ED at 14 hospitals across the UK if MI had been ruled out and hs-cTn testing stratified them as being at intermediate risk (5 ng/L to sex-specific 99th percentile). Participants were randomised to outpatient CTCA in addition to standard of care or standard of care alone. Patients who had CAD identified on CTCA were provided with lifestyle advice and a recommendation to commence preventative therapy (anti-platelet and statin therapy). Those with obstructive CAD or clinically important non-cardiac findings were offered an outpatient consultation.

The researchers found that CCTA did not reduce subsequent cardiovascular events. Over a median follow-up of 3 years, the primary endpoint of MI and cardiac death occurred in 7.0% of patients in the CTCA plus standard-of-care group and 7.3% in the standard-of-care group (adjusted HR 0.95; 95% CI 0.73 to 1.23; p=0.712). “Implementing CTCA to guide the management in this patient population is not warranted based on these findings,” concluded Prof. Mills.