Implications of Alternative Definitions of Peri-Procedural Myocardial Infarction After Coronary Revascularization
John GregsonGregg W. StoneOri Ben‐YehudaBjörn RedforsDavid E. KandzariMarie‐Claude MoriceMartin B. LeonIoanna KosmidouNicholas LemboW. Morris BrownDimitri KarmpaliotisAdrian BanningJosé Luís PomarManel SabatéCharles A. SimontonOvidiu DresslerA. Pieter KappeteinJoseph F. SabikPatrick W. SerruysStuart Pocock
Key result
Percutaneous coronary intervention resulted in a 3.6% rate of protocol-defined procedural myocardial infarction compared to 6.1% with CABG (difference -2.4%; 95% CI -4.4% to -0.5%; p=0.015).
Key Points
- To assess how disparate consensus definitions of peri-procedural myocardial infarction affect reported incidence rates and comparative clinical trial outcomes between percutaneous coronary intervention and coronary artery bypass graft surgery.
- Evaluated clinical trial cohorts undergoing percutaneous coronary intervention or coronary artery bypass grafting across standardized definitions, including the Universal Definition of Myocardial Infarction, Society for Cardiovascular Angiography and Interventions, and Academic Research Consortium criteria.
- Compared diagnostic thresholds of post-procedural cardiac biomarkers, including creatine kinase-MB and cardiac troponin, with and without complementary electrocardiographic or imaging evidence of ischemia.
- Application of different consensus definitions generated substantial discordance in peri-procedural myocardial infarction rates, significantly shifting relative safety and efficacy profiles between surgical and percutaneous revascularization.
- Definitions requiring higher biomarker elevations combined with ancillary evidence of myocardial ischemia exhibited stronger correlations with subsequent cardiovascular mortality compared to definitions based solely on isolated biomarker release.
Study Design
Type
RCT (n=1,858)
Randomization
randomized
PICO
P
Population
1,858 patients with left main coronary artery disease randomized to PCI versus CABG, evaluated for procedural myocardial infarction and 5-year mortality.
I
Intervention / Comparator
Percutaneous coronary intervention (PCI) vs Coronary artery bypass grafting (CABG)
O
Primary Outcome
Protocol definition of procedural myocardial infarction (PMIProt) — difference -2.4% (-4.4 to -0.5), p=0.015
Main Result
Effect estimate: difference -2.4% (95% CI -4.4 to -0.5)
Absolute Event Rate: 3.6% vs 6.1%
p-value: p=0.015
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“There is a lot of debate and controversy about how we best define type 4a MIs, with previous studies like EXCEL and ISCHEMIA using their own definitions. Depending on the definition used, this can change the outcomes of these trials quite significantly.”
“The biomarkers are elevating, they've not peaked. It's also very likely PCI worsens the extent of myocardial necrosis in STEMI, because it does not infrequently cause distal atherothrombotic embolization. But it's very difficult to pick it up.”
Implication
Comparative analysis reveals major incidence discrepancies across myocardial infarction definitions after revascularization, highlighting the critical need for uniform trial criteria.
Abstract
BACKGROUND Varying definitions of procedural myocardial infarction (PMI) are in widespread use. OBJECTIVES This study sought to determine the rates and clinical relevance of PMI using different definitions in patients with left main coronary artery disease randomized to percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) surgery in the EXCEL (Evaluation of XIENCE versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial. METHODS The pre-specified protocol definition of PMI (PMIProt) required a large elevation of creatine kinase-MB (CK-MB), with identical threshold for both procedures. The Third Universal Definition of MI (types 4a and 5) (PMIUD) required lesser biomarker elevations but with supporting evidence of myocardial ischemia, different after PCI and CABG. For the PMIUD, troponins were used preferentially (available in 49.5% of patients), CK-MB otherwise. The multivariable relationship between each PMI type and 5-year mortality was determined. RESULTS PMIProt occurred in 34 of 935 (3.6%) patients after PCI and 56 of 923 (6.1%) patients after CABG (difference -2.4%; 95% confidence interval [CI]: -4.4% to -0.5%; p = 0.015). The corresponding rates of PMIUD were 37 (4.0%) and 20 (2.2%), respectively (difference 1.8%; 95% CI: 0.2% to 3.4%; p = 0.025). Both PMIProt and PMIUD were associated with 5-year cardiovascular mortality (adjusted hazard ratio [HR]: 2.18 [95% CI: 1.13 to 4.23] and 2.87 [95% CI: 1.44 to 5.73], respectively). PMIProt was associated with a consistent hazard of cardiovascular mortality after both PCI and CABG (pinteraction = 0.86). Conversely, PMIUD was strongly associated with cardiovascular mortality after CABG (adjusted HR: 11.94; 95% CI: 4.84 to 29.47) but not after PCI (adjusted HR: 1.14; 95% CI: 0.35 to 3.67) (pinteraction = 0.004). Results were similar for all-cause mortality and with varying PMIUD biomarker definitions. Only large biomarker elevations (CK-MB ≥10× upper reference limit and troponin ≥70× upper reference limit) were associated with mortality. CONCLUSIONS The rates of PMI after PCI and CABG vary greatly with different definitions. In the EXCEL trial, the pre-specified PMIProt was associated with similar hazard after PCI and CABG, whereas PMIUD was strongly associated with mortality after CABG but not after PCI. (EXCEL Clinical Trial [EXCEL]; NCT01205776).
Discussion
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Cite This Study
Gregson et al. (2020) conducted an RCT in Left main coronary artery disease (n=1,858). Percutaneous coronary intervention (PCI) vs. Coronary artery bypass grafting (CABG) was evaluated on Protocol definition of procedural myocardial infarction (PMIProt) (difference -2.4%, 95% CI -4.4 to -0.5, p=0.015). Percutaneous coronary intervention resulted in a 3.6% rate of protocol-defined procedural myocardial infarction compared to 6.1% with CABG (difference -2.4%; 95% CI -4.4% to -0.5%; p=0.015).