Author + information
- Received January 11, 2012
- Revision received August 17, 2012
- Accepted August 20, 2012
- Published online February 1, 2013.
- Jason S. Chinitz, MD⁎,
- Debbie Chen, BA⁎,
- Parag Goyal, MD⁎,
- Sean Wilson, MD⁎,
- Fahmida Islam, BA⁎,
- Thanh Nguyen, PhD†,
- Yi Wang, PhD†,
- Sandra Hurtado-Rua, PhD‡,
- Lauren Simprini, MD§,
- Matthew Cham, MD∥,
- Robert A. Levine, MD¶,
- Richard B. Devereux, MD⁎ and
- Jonathan W. Weinsaft, MD⁎,†,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Jonathan W. Weinsaft, Weill Cornell Medical College, Starr-4, 525 East 68th Street, New York, New York 10021
Objectives This study sought to assess patterns and functional consequences of mitral apparatus infarction after acute myocardial infarction (AMI).
Background The mitral apparatus contains 2 myocardial components: papillary muscles and the adjacent left ventricular (LV) wall. Delayed-enhancement cardiac magnetic resonance (DE-CMR) enables in vivo study of inter-relationships and potential contributions of LV wall and papillary muscle infarction (PMI) to mitral regurgitation (MR).
Methods Multimodality imaging was performed: CMR was used to assess mitral geometry and infarct pattern, including 3D DE-CMR for PMI. Echocardiography was used to measure MR. Imaging occurred 27 ± 8 days after AMI (CMR, echocardiography within 1 day).
Results A total of 153 patients with first AMI were studied; PMI was present in 30% (n = 46 [72% posteromedial, 39% anterolateral]). When stratified by angiographic culprit vessel, PMI occurred in 65% of patients with left circumflex, 48% with right coronary, and only 14% of patients with left anterior descending infarctions (p <0.001). Patients with PMI had more advanced remodeling as measured by LV size and mitral annular diameter (p <0.05). Increased extent of PMI was accompanied by a stepwise increase in mean infarct transmurality within regional LV segments underlying each papillary muscle (p <0.001). Prevalence of lateral wall infarction was 3-fold higher among patients with PMI compared to patients without PMI (65% vs. 22%, p <0.001). Infarct distribution also impacted MR, with greater MR among patients with lateral wall infarction (p = 0.002). Conversely, MR severity did not differ on the basis of presence (p = 0.19) or extent (p = 0.12) of PMI, or by angiographic culprit vessel. In multivariable analysis, lateral wall infarct size (odds ratio 1.20/% LV myocardium [95% confidence interval: 1.05 to 1.39], p = 0.01) was independently associated with substantial (moderate or greater) MR even after controlling for mitral annular (odds ratio 1.22/mm [1.04 to 1.43], p = 0.01), and LV end-diastolic diameter (odds ratio 1.11/mm [0.99 to 1.23], p = 0.056).
Conclusions Papillary muscle infarction is common after AMI, affecting nearly one-third of patients. Extent of PMI parallels adjacent LV wall injury, with lateral infarction—rather than PMI—associated with increased severity of post-AMI MR.
This work was supported by Lantheus Medical Imaging, and a Doris Duke Clinical Scientist Development Award (K23 HL102249-01) to Dr. Weinsaft. The authors have reported they have no relationships relevant to the contents of this paper to disclose.
- Received January 11, 2012.
- Revision received August 17, 2012.
- Accepted August 20, 2012.
- American College of Cardiology Foundation