Author + information
- Guido Parodi, MD, PhD∗ ( and )
- Carlo Di Mario, MD, PhD
- ↵∗Cardiovascular and Thoracic Department, Careggi University Hospital, Largo Brambilla 3, 50141, Florence, Italy
We read with interest the results of the EXPLORE (Evaluating Xience and Left Ventricular Function in Percutaneous Coronary Intervention on Occlusions After ST-Elevation Myocardial Infarction) trial (1) showing no benefit on the primary end points (left ventricular function and end-diastolic volume at 4 months) for routine treatment with percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) early after primary PCI. The promoters of this randomized trial were the first to show that the presence of a CTO in a nonculprit vessel more than doubles mortality after primary angioplasty and were certainly disappointed by the negative outcome. We are very worried that the final message to the interventional community will be: do not open CTO of nonculprit vessels after ST-segment elevation myocardial infarction (STEMI), with the possible exception of left anterior descending artery CTOs. The authors emphasize potential benefit from early PCI of the left anterior descending artery CTO which was present in only 36 patients of the active arm. We would like to recommend considering with more caution the sub-group analysis results of a formally negative study (not meeting the primary endpoint in the whole study population): the use of sub-group analyses should be exploratory at best due to the high risk of biases (2). The lesson to learn from this trial is that rapid treatment of a CTO during the index admission is probably not realistic and leads to the inability to use refined CTO techniques in long and complex procedures poorly tolerated soon after STEMI: a 73% procedural success rate is far from the optimal standards reported for elective procedures in dedicated centers. An immediate treatment of the CTO precludes the possibility to assess residual symptoms and signs of myocardial ischemia and tissue viability, which are the most common drivers of CTO PCI in current clinical practice and were not adequately considered in the study protocol. Finally, the interval for reassessment of left ventricular function after recanalization might be too short to expect full recovery (3). Thus, the EXPLORE trial, certainly added to the current knowledge, but we are still far from being able to optimally select the appropriate timing and the subsets of STEMI patients who may benefit the most from CTO PCI (4).
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose. William Lombardi, MD, served as Guest Editor for this paper.
- 2017 American College of Cardiology Foundation
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