Time course of infarct healing and left ventricular remodelling in patients with reperfused ST segment elevation myocardial infarction using comprehensive magnetic resonance imaging
ABSTRACT To describe the time course of myocardial infarct (MI) healing and left ventricular (LV) remodelling and to assess factors predicting LV remodelling using cardiac MRI.
In 58 successfully reperfused MI patients, MRI was performed at baseline, 4 months (4M), and 1 year (1Y) post MI RESULTS: Infarct size decreased between baseline and 4M (p < 0.001), but not at 1Y; i.e. 18 ± 11%, 12 ± 8%, 11 ± 6% of LV mass respectively; this was associated with LV mass reduction. Infarct and adjacent wall thinning was found at 4M, whereas significant remote wall thinning was measured at 1Y. LV end-diastolic and end-systolic volumes significantly increased at 1Y, p < 0.05 at 1Y vs. baseline and vs. 4M; this was associated with increased LV sphericity index. No regional or global LV functional improvement was found at follow-up. Baseline infarct size was the strongest predictor of adverse LV remodelling.
Infarct healing, with shrinkage of infarcted myocardium and wall thinning, occurs early post-MI as reflected by loss in LV mass and adjacent myocardial remodelling. Longer follow-up demonstrates ongoing remote myocardial and ventricular remodelling. Infarct size at baseline predicts long-term LV remodelling and represents an important parameter for tailoring future post-MI pharmacological therapies designed to prevent heart failure.
- SourceAvailable from: Peder Sörensson
[Show abstract] [Hide abstract]
- "Masci et al. concluded that infarct size rather than location and salvage index predicted LV remodeling in STEMI patients [32,33]. Only nine of the patients in the present study met the remodeling criteria (a consistent increase in ESV >15%) and small infarct sizes is the most reasonable explanation [24,31,32]. In addition the vast majority of the present patients were treated with beta-blockers and angiotensin converting enzyme inhibitors, pharmacological agents known to counteract remodeling. "
ABSTRACT: Ischemic postconditioning (PostC), reperfusion in brief cycles, is known to induce short-term reduction in infarct size in patients with ST elevation myocardial infarction (STEMI), especially among those with large myocardium at risk (MaR). The aim of the present study was to investigate the long-term effect of PostC on infarct size and left ventricular ejection fraction (LVEF). Sixty-eight patients with a first STEMI were randomised to primary percutaneous coronary intervention (PCI) (n = 35) or PCI followed by PostC (n = 33). MaR was determined as abnormally contracting segments on left ventricular angiogram. Cardiac magnetic resonance was performed at 3 and 12 months for the determination of infarct size and LVEF. Overall there was no difference in infarct size expressed in percentage of MaR between patients randomised to the control (31%; 23, 41) and PostC (31%; 23, 43) groups at 12 months. Likewise there was no difference in LVEF between control (49%; 41, 55) and PostC (52%; 45, 55). In contrast, patients in the PostC group with MaR in the upper quartile had a significantly smaller infarct size (29%; 18, 38) than those in the control group (40%; 34, 48; p < 0.05) at 12 months. In these patients LVEF was higher in the PostC (47%; 43, 50) compared to the control group (38%; 34, 42; p < 0.01). In this long-term follow-up study PostC did not reduce infarct size in relation to MaR or improved LVEF in the overall study population. However, the present data suggest that PostC exerts long-term beneficial effects in patients with large MaR thereby extending previously published short-term observations. Trial registration Karolinska Clinical Trial Registration (http://www.kctr.se). Unique identifier: CT20080014BMC Cardiovascular Disorders 03/2013; 13(1):22. DOI:10.1186/1471-2261-13-22 · 1.50 Impact Factor
[Show abstract] [Hide abstract]
- "Infarct size alone is a rigorous, independent predictor of MACE-free survival that can be used to classify patients as at-risk (e.g., infarct size ≥ 18.5%) or not at-risk.14 Even with maximum medical care, however, once an infarct is established its size does not change.17 While long-term adverse neurohormonal responses can be countered with β blockers and ACE-inhibitors and the likelihood of recurrent ischemic events can be decreased with aggressive secondary prevention,18 no therapy currently available can reduce the size of an established infarct. "
ABSTRACT: Cardiosphere-derived cells (CDCs) are under clinical development and are currently being tested in a clinical trial enrolling patients who have undergone a myocardial infarction. CDCs are presently administered via infusion into the infarct-related artery and have been shown in early clinical trials to be effective agents of myocardial regeneration. This review describes the administration of CDCs in a hyaluronan-gelatin hydrogel via myocardial injection and the subsequent improvements in therapeutic benefit seen in animal models. Development of a next generation therapy involving the combination of CDCs and hydrogel is discussed.Biomatter 01/2013; 3(1). DOI:10.4161/biom.24490
[Show abstract] [Hide abstract]
- "ECG gated and acquired during breath holds, dynamic cine MRI (b–SSFP) sequences provide a non–invasive, accurate and reproducible alternative to conventional echocardiography for calculating ventricular volumes and function and visualizing regional wall motion and contraction patterns. Thus, cine MRI should be considered as a fast and robust imaging modality for both daily clinical routine and research purposes [10, 11]. With techniques as real–time non–gated cine sequences, problems like the presence of atrial fibrillation or the incapacity for breath holding are now mostly overcome. "
ABSTRACT: Cardiac magnetic resonance imaging (MRI) has emerged as a prime player in the clinical and preclinical detection of ischemic heart disease (IHD) as well in the prognosis assessment by offering a comprehensive approach for all spectrums of coronary artery disease (CAD) patients. The aim of this review is to provide the reader a state–of–the art on how the newest cardiac MRI techniques can be used to study IHD patients.In patients with suspected/stable CAD, functional and perfusion imaging both at rest and during vasodilatatory stress (adenosine, dypiridamole)/dobutamine stress can accurately depict ischemic myocardium secondary to significant coronary artery stenosis.In patients with acute MI, MRI is a robust tool for differentiating and sizing the jeopardized and the infarcted myocardium by using a combination of functional, edema, perfusion and Gd contrast imaging. Moreover, important prognostic factors like myocardial salvage, the presence of microvascular obstruction (MVO), post reperfusion myocardial hemorrhage, RV involvement and infarct related complications can be assessed in the same examination. In patients with chronic ischemic cardiomyopathy, the role of the MRI extends from diagnosis by means of Gadolinium contrast scar imaging to therapy and prognosis by functional assessment and viability testing with rest and dobutamine stress imaging.In all the circumstances mentioned, MRI derived information has been proven valuable in every day clinical decision making and prognosis assessment. Thus, MRI is becoming more and more an accepted alternative to other imaging modalities both in the acute and chronic setting.Journal of medicine and life 11/2011; 4(4):330-45.