According to the European Society of Cardiology (ESC Guidelines 2021) an early invasive strategy is recommended (<24h) for high-risk patients with acute coronary syndrome with no ST elevation (NSTE-ACS), namely patients presenting a rise or fall in cardiac troponin, dynamic ST- or T-wave changes and GRACE risk score >140. Early intervention (<2h) is reserved for unstable or very high-risk patients.
This early intervention strategy recommended by guidelines for high-risk patients mainly comes from subgroup analyses based of GRACE score as reported by the TIMACS and VERDICT studies. Therefore, the optimal timing for an invasive strategy is yet to be established.
The aim of this study recently published in the European Heart Journal was to carry out a meta-analysis to compare the efficacy and safety of early vs delayed intervention in NSTE-ACS patients.
Researchers looked into 17 randomized studies including 5215 patients undergoing early intervention (average 3.43RRs) and 4994 undergoing delayed intervention (average 41.3RRs).
Primary end point was all cause mortality. Secondary end points included AMI, recurrent ischemia, hospitalization for cardiac failure, repeat revascularization, major bleeding, stroke, and hospitalization days.
There were no significant differences in primary end point of all-cause mortality (RR: 0.90, CI 95% 0.78-1.04). Neither were there significant differences between the secondary end points of AMI (RR: 0.86, CI 95% 0.63-1.16), hospitalization for cardiac failure (RR: 0.66, CI 95% 0.43-1.03), repeat revascularization (RR: 1.04, CI 95% 0.88-1.23), major bleeding (RR: 0.86, CI 95% 0.68-1.09) or stroke (RR: 0.95, CI 95% 0.59-1.54).
When looking at recurrent ischemia, there was lower events rate in the early intervention branch (RR: 0.57, CI 95% 0.40-0.81), as well as shorter hospital stay, with average 86hrs (early intervention) vs 111hrs (delayed intervention) (mean difference: -22hrs, CI 95% -37hsr a -8hrs; P=0.003).
Many systematic reviews assessing the outcomes of invasive vs conservative strategies in the treatment of NSTE-ACS have already been published. However, the ideal timing has not yet been established, there simply is no conclusive evidence.
This meta-analysis has shown early intervention did not reduce neither primary end point, nor most of secondary end points. However, researchers did observe reduced recurrent ischemia (ischemia with insignificant clinical impact, not reducing mortality) and hospital stay.
Should these outcomes persuade us to question the safety and cost-effectiveness of routine early intervention, enough to modify guideline recommendation? Certainly not, considering the limitations and biases of a meta-analysis with heterogeneous studies and the exclusion of individual patient-level data.
We must continue to look into patients defined as high-risk to be able to establish who will benefit from an early strategy.
Dr. Omar Tupayachi.
Member of the editorial board of SOLACI.org.
Original Title: Timing of invasive strategy in non-ST-elevation acute coronary syndrome: a meta-analysis of randomized controlled trials
Source: Kite TA, et al. Timing of invasive strategy in non-ST-elevation acute coronary syndrome: a meta-analysis of randomized controlled trials. Eur Heart J [Internet]. 2022; Disponible en: https://academic.oup.com/eurheartj/advance-article/doi/10.1093/eurheartj/ehac213/6581488.
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