Mechanical Left Ventricular Unloading to Reduce Infarct Size During Acute Myocardial Infarction: Insight from Preclinical and Clinical Studies

Background: Assessment of cardiac biomarker release has been traditionally used to estimate the size of myocardial damage after acute myocardial infarction (AMI). However, the significance of cardiac biomarkers in the setting of primary percutaneous coronary intervention (PCI) has not been systematically studied in a large patient cohort. We evaluated the usefulness of serial and single time-point measures of various cardiac biomarkers (creatine kinase (CK), CK-MB, troponin T and I) in predicting infarct size and left ventricular ejection fraction (LVEF) after primary PCI. Methods: EVOLVE (Evaluation of MCC-135 for Left Ventricular Salvage in AMI) was a randomized double-blind, placebo-controlled trial comparing the efficacy of intracellular calcium modulator as an adjunct to primary PCI in patients with first large AMI. Levels of cardiac biomarkers (CK, CK-MB mass, troponin T and I) were determined in 375 patients at baseline before PCI and 2, 4, 12, 24, 48 and 72 hours thereafter. Single photon emission computed tomography imaging was performed to measure infarct size and LVEF on day 5. Results: Area under curve and peak concentrations of all cardiac markers: CK, CK-MB mass, troponin T and troponin I were significantly correlated with myocardial infarct size and LVEF determined on day 5 (Spearman correlation, all P< 0.001; Table ). Troponin I, however provided the best predictor and a single measure at 72 hr was a strong indicator of both infarct size and LVEF. Using receiver operator characteristics curve, troponin I cutoff value of >55 pg/mL at 72 hr has 90% sensitivity and 70% specificity for detection of large infarct size≥10% ( c =0.88; P< 0.001). Conclusions: Plasma levels of CK, CK-MB, troponin T and troponin I remain useful predictors of infarct size and cardiac function in the era of primary PCI for AMI. A single measurement of circulating troponin I at 72 hours can provide an effective and convenient indicator of infarct size and LVEF in clinical practice. Correlation of cardiac biomarkers with Day 5 SPECT determined infarct size and LVEF

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Abstract 18996: Impact of Infarct Size on Left Ventricular Diastolic Function Following Acute Myocardial Infarction

Circulation ◽

10.1161/circ.132.suppl_3.18996 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Andrew Lin ◽

Christopher Kwan ◽

Kristyan Guppy-Coles ◽

Joanne Sippel ◽

John Atherton ◽

...

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Infarct Size ◽

Diastolic Dysfunction ◽

Diastolic Function ◽

Troponin I ◽

Left Ventricular Diastolic Function ◽

Left Ventricular ◽

Ventricular Diastolic Function ◽

St Elevation

Introduction: Severe left ventricular diastolic dysfunction is associated with worse prognosis after acute myocardial infarction (MI). Twenty percent of patients have a restrictive filling pattern (RFP) following MI, and this is associated with a fourfold increase in mortality. The determinants of diastolic function in this setting are not well defined. Aim: We sought to determine the correlation between enzymatic infarct size and RFP in patients with a first ever MI. We hypothesized that a larger infarct size would result in greater impairment of left ventricular diastolic function. Methods: Data analysis was performed on consecutive patients admitted with first ever non-ST elevation MI (NSTEMI) or ST-elevation MI (STEMI) to a single large tertiary referral hospital from January 2013 to December 2014. All patients underwent coronary angiography during the index admission. Infarct size was determined by peak troponin I. Doppler transmitral flow pattern was obtained from the initial transthoracic echocardiogram performed within 48 hours of admission. RFP was defined as: E/A ratio >2.0 and/or E-wave deceleration time <160ms (American Society of Echocardiography Guidelines 2009). Results: Data were available on 645 consecutive patients who underwent coronary angiography for MI. We excluded 160 patients with a previous MI. Of the remaining 485 patients (mean age 62±13 years; mean left ventricular ejection fraction (LVEF) 53±12%), there were 338 NSTEMIs (70%) and 147 STEMIs (30%). PCI was performed in 360 (74%) patients (single vessel (82%), ≥2 vessels (18%)); coronary artery bypass surgery in 58 (13%); and medical management in 67 (13%). Sixty-nine patients (14.4%) had RFP; 52% of these had a LVEF ≥45%. Peak troponin I levels were higher in the RFP group (31.8±30.9μg/L vs 16.8±25.2μg/L, p=<0.001). On multivariate analysis, infarct size by peak troponin I (OR 1.02, 95%CI 1.00-1.03, p=0.026) and low LVEF (OR 0.95, 95%CI 0.91-0.99, p=0.015) were the only independent predictors of RFP. Conclusion: Infarct size was a major determinant of diastolic dysfunction following first ever MI. Whilst LV systolic dysfunction was strongly associated with impaired diastolic function, 52% of patients with severe diastolic dysfunction had relatively preserved LVEF.

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Cardiac surgery in acute myocardial infarction: crystalloid versus blood cardioplegia – an experimental study

Journal of Cardiothoracic Surgery ◽

10.1186/s13019-020-1058-9 ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

Andreas Boening ◽

Maximilian Hinke ◽

Martina Heep ◽

Kerstin Boengler ◽

Bernd Niemann ◽

...

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Cardiac Surgery ◽

Cardiac Function ◽

Infarct Size ◽

Left Ventricular ◽

Coronary Artery Ligation ◽

Cardioplegic Arrest ◽

Blood Cardioplegia ◽

Cardioplegia Solution

Abstract Background Because hearts in acute myocardial infarction are often prone to ischemia-reperfusion damage during cardiac surgery, we investigated the influence of intracellular crystalloid cardioplegia solution (CCP) and extracellular blood cardioplegia solution (BCP) on cardiac function, metabolism, and infarct size in a rat heart model of myocardial infarction. Methods Following euthanasia, the hearts of 50 rats were quickly excised, cannulated, and inserted into a blood-perfused isolated heart apparatus. A regional myocardial infarction was created in the infarction group (18 hearts) for 120 min; the control group (32 hearts) was not subjected to infarction. In each group, either Buckberg BCP or Bretschneider CCP was administered for an aortic clamping time of 90 min. Functional parameters were recorded during reperfusion: coronary blood flow, left ventricular developed pressure (LVDP) and contractility (dp/dt max). Infarct size was determined by planimetry. The results were compared between the groups using analysis of variance or parametric tests, as appropriate. Results Cardiac function after acute myocardial infarction, 90 min of cardioplegic arrest, and 90 min of reperfusion was better preserved with Buckberg BCP than with Bretschneider CCP relative to baseline (BL) values (LVDP 54 ± 11% vs. 9 ± 2.9% [p = 0.0062]; dp/dt max. 73 ± 11% vs. 23 ± 2.7% [p = 0.0001]), whereas coronary flow was similarly impaired (BCP 55 ± 15%, CCP 63 ± 17% [p = 0.99]). The infarct in BCP-treated hearts was smaller (25% of myocardium) and limited to the area of coronary artery ligation, whereas in CCP hearts the infarct was larger (48% of myocardium; p = 0.029) and myocardial necrosis was distributed unevenly to the left ventricular wall. Conclusions In a rat model of acute myocardial infarction followed by cardioplegic arrest, application of BCP leads to better myocardial recovery than CCP.

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The Effect Of Fibrinolysis In The Early Stage Of Acute Myocardial Infarction

10.1055/s-0038-1652450 ◽

1981 ◽

Author(s):

K Genth ◽

J Frank ◽

J Schaefer ◽

V Korten ◽

D Heene

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Infarct Size ◽

Ventricular Function ◽

Early Stage ◽

Myocardial Infarct ◽

Interventricular Septum ◽

Left Ventricular ◽

Myocardial Infarct Size ◽

Time To Peak

The influence of streptokinase (SK) on myocardial infarct size and left ventricular function after acute myocardial infarction was investigated. 21 patients with myocardial infarction received SK (SK-group), 27 patients underwent conventional therapy (C-group). In both groups therapy started within 8 hours after onset of chest pain. In the SK-group initially 250 000 IU were administered intravenously, followed by a maintenance dose of 100 000 IU/h, lasting 15 hours. Blood samples at 8 hours intervals were collected for 3 days for serial CPK-analysis to calculate infarct size (I=∫f(t)×dt×K×bw). M-mode echocardiography was taken before start of t her a py and after 15, 24, 48 and 72 hours. AOP and heart rate were recorded continuously. Infarct size was 47±12g in the SK-group and 84±25g in the C-group (p<0.05). The average time to peak blood CPK-activity was 24 hours in the SK-group and 40 hours in the C-group. Peak CPK-level was significantly higher (p<0.5) in the SK-group (841±160U/l) than in the C-group (532±13 8 U / l ) . In 16 patients of the SK-group short periods of ventricular tachycardia were recorded during the period of fibrinolysis. Before therapy all patients showed abnormal motion of the posterior left ventricular wall and/or the interventricular septum, detected by echocardiography. 14 patients showed after fibrinolysis an improved or normalized motion.The results indicate that early fibrinolysis may reopen the occluded coronary artery. Reperfusion of the ischemic perfusion area may salvage jeo pardized myocardium, therefore infarct size was reduced and ventricular function improved.

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2230Results from the CAMI1 Study: selective CRP apheresis as a new treatment option in acute myocardial infarction

European Heart Journal ◽

10.1093/eurheartj/ehz748.0126 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

C Garlichs ◽

J Torzewski ◽

A Sheriff ◽

C Pfluecke ◽

H Darius ◽

...

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Infarct Size ◽

Plasma Levels ◽

Myocardial Damage ◽

Left Ventricular ◽

Left Ventricular Ejection ◽

Study Endpoint ◽

Infarction Size ◽

Myocardial Infarction Size

Abstract Background Inflammation is increasingly recognized as an important pathogenic feature in cardiovascular disease. In patients with STEMI, C-reactive protein (CRP), the prototype human acute phase protein, is a marker of poor prognosis and independently predicts 30-day mortality. In STEMI, CRP may indeed be intimately involved in myocardial damage by activating the complement system in the ischemic tissue. In animal experiments, CRP removal after STEMI reduces infarct size and results in a significantly better left ventricular ejection fraction (LVEF). Recently, in the multi-center matched-control pilot study on CRP apheresis in Acute Myocardial Infarction (CAMI1), a newly designed CRP adsorber has been demonstrated to efficiently and selectively lower CRP plasma levels in humans. Here, we present preliminary data of the ongoing trial. Methods Up to the present day, 67 STEMI patients were enrolled in the study following complete coronary revascularization. 32 patients received CRP apheresis, whereas 35 patients treated by standard protocols served as controls. CRP apheresis started 24±12 h and 48±12 h after onset of symptoms. In case of a rapid increase in CRP plasma levels following the 2nd session, a 3rd session was carried out another 24 h later. In each apheresis session, 6000 ml plasma was treated via peripheral venous access. Primary study endpoint was myocardial infarction size as determined by Cardiac Magnetic Resonance Imaging (MRI) 5±3 days after STEMI. Results Apheresis sessions were well tolerated with no relevant side effects. Peak CRP plasma levels after STEMI ranged from 12 mg/l to 279 mg/l. The peak CRP level after AMI can be calculated precisely with at 2–3 CRP quantifications during the first 24 h after the onset of symptoms. The regression coefficient for this analysis is 0.95. This mathematical step allows for the comparison of the CRP-apheresis group and the controls on the basis of their individual CRP peak levels. The statistical evaluation shows that the apheresis patients no longer correlate with the control with regard to the endpoints infarct size, LVEF, longitudinal strain and circumferential strain. They perform significantly better at all endpoints. The CRP apheresis reduced the development of myocardial damage. Conclusions Here, an unequivocal association between infarct size and CRP is demonstrated for the first time. CRP apheresis following STEMI is feasible and safe. Our preliminary results in a small cohort show a significant beneficial effect of CRP apheresis on myocardial infarction size and wall motion. Selective CRP apheresis may emerge as a new therapeutic approach in the treatment of acute myocardial infarction.

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