Distal protection device aggravated microvascular obstruction evaluated by cardiac MR after primary percutaneous intervention for ST-elevation myocardial infarction

Impact of thrombus aspiration on left ventricular remodeling and function in patients with ST-segment elevation myocardial infarction: A meta-analysis of randomized controlled trials

BACKGROUND

Routine thrombus aspiration (TA) does not improve clinical outcomes in patients with ST-segment-elevation myocardial infarction (STEMI), although data from meta-analyses suggest that patients with high thrombus burden may benefit from it. The impact of TA on left ventricular (LV) functional recovery and remodeling after STEMI remains controversial. We aimed to pool data from randomized controlled trials (RCTs) on the impact of TA on LV function and remodeling after primary percutaneous coronary intervention (pPCI).

METHODS

PubMed and CENTRAL databases were scanned for eligible studies. Primary outcome measures were: LV ejection fraction (LVEF), LV end diastolic volume (LVEDV), LV end systolic volume (LVESV) and wall motion score index (WMSI). A primary pre-specified subgroup analysis was performed comparing manual TA with mechanical TA.

RESULTS

A total of 28 studies enrolling 4990 patients were included. WMSI was lower in TA group than in control (mean difference [MD] -0.11, 95% confidence interval [CI] -0.19 to -0.03). A greater LVEF (MD 1.91, 95% CI 0.76 to 3) and a smaller LVESV (MD -6.19, 95% CI -8.7 to -3.6) were observed in manual TA group compared to control. Meta regressions including patients with left anterior descending artery (LAD) involvement showed an association between TA use and the reduction of both LVEDV and LVESV (z = -2.13, p = 0.03; z = -3.7, p < 0.01) and the improvement in myocardial salvage index (z = 2.04, p = 0.04).

CONCLUSION

TA is associated with improved LV function. TA technique, total ischemic time and LAD involvement appears to influence TA benefit on post-infarction LV remodeling.

The prognostic value of myocardial salvage index by cardiac magnetic resonance in ST-segment elevation myocardial infarction patients: a systematic review and meta-analysis

OBJECTIVE

To assess the prognostic value of myocardial salvage index (MSI) by cardiac magnetic resonance (CMR) in ST-segment elevation myocardial infarction (STEMI) patients.

METHODS

We systematically searched PubMed, Embase, Web of Science, Cochrane Central, China National Knowledge Infrastructure, and Wanfang Data to identify primary studies reporting MSI in STEMI patients with major adverse cardiovascular events (MACE) comprised of death, myocardial reinfarction, and congestive heart failure. The MSI and MACE rates were pooled. The bias of risk was assessed using the Quality In Prognosis Studies tool. The evidence level was rated based on the meta-analysis of hazard ratio (HR) and 95% confidence interval (CI) of MSI for predicting MACE.

RESULTS

Eighteen studies were included covering twelve unique cohorts. Eleven cohorts measured MSI using T2-weighted imaging and T1-weighted late gadolinium enhancement, while one cohort applied T2-mapping and T1-mapping. The pooled MSI (95% CI) was 44% (39 to 49%; 11 studies, 2946 patients), and the pooled MACE rate (95% CI) was 10% (7 to 14%; 12 studies, 311/3011 events/patients). Seven prognostic studies overall showed low risk of bias. The HR (95% CI) per 1% increase of MSI for MACE was 0.95 (0.92 to 0.98; 5 studies, 150/885 events/patients), and HR (95% CI) of MSI < median versus MSI > median for MACE was 5.62 (3.74 to 8.43; 6 studies, 166/1570 events/patients), both rated as weak evidence.

CONCLUSIONS

MSI presents potential in predicting MACE in STEMI patients. The prognostic value of MSI using advanced CMR techniques for adverse cardiovascular events needs further investigation.

CLINICAL RELEVANCE STATEMENT

Seven studies supported the MSI to serve as a predictor for MACE in STEMI patients, indicating its potential as a risk stratification tool to help manage expectations for these patients in clinical practice.

KEY POINTS

• The pooled infarct size (95% CI) and area at risk (95% CI) were 21% (18 to 23%; 11 studies, 2783 patients) and 38% (34 to 43%; 10 studies, 2022 patients), respectively. • The pooled rates (95% CI) of cardiac mortality, myocardial reinfarction, and congestive heart failure were 2% (1 to 3%; 11 studies, 86/2907 events/patients), 4% (3 to 6%; 12 studies, 127/3011 events/patients), and 3% (1 to 5%; 12 studies, 94/3011 events/patients), respectively. • The HRs (95% CI) per 1% increase of MSI for cardiac mortality and congestive heart failure were 0.93 (0.91 to 0.96; 1 study, 14/202 events/patients) and 0.96 (0.93 to 0.99; 1 study, 11/104 events/patients), respectively, but the prognostic value of MSI for myocardial re-infraction has not been measured.

What can we do to optimize mitochondrial transplantation therapy for myocardial ischemia-reperfusion injury?

Mitochondrial transplantation is a promising solution for the heart following ischemia-reperfusion injury due to its capacity to replace damaged mitochondria and restore cardiac function. However, many barriers (such as inadequate mitochondrial internalization, poor survival of transplanted mitochondria, few mitochondria colocalized with cardiac cells) compromise the replacement of injured mitochondria with transplanted mitochondria. Therefore, it is necessary to optimize mitochondrial transplantation therapy to improve clinical effectiveness. By analogy, myocardial ischemia-reperfusion injury is like a withered flower, it needs to absorb enough nutrients to recover and bloom. In this review, we present a comprehensive overview of "nutrients" (source of exogenous mitochondria and different techniques for mitochondrial isolation), "absorption" (mitochondrial transplantation approaches, mitochondrial transplantation dose and internalization mechanism), and "flowering" (the mechanism of mitochondrial transplantation in cardioprotection) for myocardial ischemia-reperfusion injury.

Intracoronary artery retrograde thrombolysis combined with percutaneous coronary interventions for ST-segment elevation myocardial infarction complicated with diabetes mellitus: A case report and literature review

Background

The management of a large thrombus burden in patients with acute myocardial infarction and diabetes is still a worldwide problem.

Case presentation

A 74-year-old Chinese woman presented with ST-segment elevation myocardial infarction (STEMI) complicated with diabetes mellitus and hypertension. Angiography revealed massive thrombus formation in the mid-segment of the right coronary artery leading to vascular occlusion. The sheared balloon was placed far from the occlusion segment and urokinase (100,000 u) was administered for intracoronary artery retrograde thrombolysis, and thrombolysis in myocardial infarction (TIMI) grade 3 blood flow was restored within 7 min. At last, one stent was accurately implanted into the culprit’s vessel. No-reflow, coronary slow flow, and reperfusion arrhythmia were not observed during this process.

Conclusion

Intracoronary artery retrograde thrombolysis (ICART) can be effectively and safely used in patients with STEMI along with diabetes mellitus and hypertension, even if the myocardial infarction exceeds 12 h (REST or named ICART ClinicalTrials.gov number, ChiCTR1900023849).

Prognostic value of the myocardial salvage index measured by T2-weighted and T1-weighted late gadolinium enhancement magnetic resonance imaging after ST-segment elevation myocardial infarction: A systematic review and meta-regression analysis

In all patients with ST-segment elevation myocardial infarction, risk stratification should be performed before discharge. The measurement of therapy efficiency with magnetic resonance imaging has been proposed as part of the risk assessment, but it has not been adopted widely. This meta-analysis was conducted to summarize published data on the prognostic value of the proportion of salvaged myocardium inside previously ischemic myocardium (myocardial salvage index) measured by T2-weighted and T1-weighted late gadolinium enhancement magnetic resonance imaging after ST-segment elevation myocardial infarction. Random and mixed effects models were used for analyzing the data of 10 studies with 2,697 patients. The pooled myocardial salvage index, calculated as the proportion of non-necrotic myocardium inside edematous myocardium measured by T2-weighted and T1-weighted late gadolinium enhancement MRI, was 43.0% (95% confidence interval: 37.4, 48.6). The pooled length of follow-up was 12.3 months (95% confidence interval: 7.0, 17.6). The pooled incidence of major cardiac events during follow-up, defined as cardiac death, nonfatal myocardial infarction, or admission for heart failure, was 10.6% (95% confidence interval: 5.7, 15.5). The applied mixed effects model showed an absolute decrease of 1.7% in the incidence of major cardiac events during follow-up (95% confidence interval: 1.6, 1.9) with every 1% of increase in the myocardial salvage index. The heterogeneity between studies was considerable (τ = 21.3). Analysis of aggregated follow-up data after ST-segment elevation myocardial infarction suggests that the myocardial salvage index measured by T2-weighted and T1-weighted late gadolinium enhancement magnetic resonance imaging provides prognostic information on the risk of major cardiac events, but considerable heterogeneity exists between studies.

Efficacy of IntraCoronary Erythropoietin Delivery BEfore Reperfusion-Gauging Infarct Size in Patients with Acute ST-segment Elevation Myocardial Infarction (ICEBERG)

Previous clinical studies have shown inconsistent results regarding the effect of erythropoietin in ST-segment elevation myocardial infarction (STEMI). This study investigated whether directed intracoronary infusion of darbepoetin-α into ischemic myocardium before reperfusion would reduce infarct size or post-infarct remodeling in STEMI patients.Eighty STEMI patients received one of the following treatments simultaneously with the first balloon inflation: intracoronary darbepoetin-α 300 μg (n = 40) or saline (n = 40), administered via the over-the-wire balloon system. The primary endpoint was infarct size estimated by serial cardiac enzyme levels after procedure. The secondary endpoints were (1) infarct size and proportion of salvaged myocardium measured with cardiac magnetic resonance (CMR) at baseline; (2) post-infarct remodeling (PIR), defined as an increase in left ventricular end-diastolic volume more than 20% at 4 months compared to the baseline on CMR; and (3) composite cardiovascular endpoints assessed at 4 months.The peak CK-MB [median 270.0 (interquartile range 139.8-356.3) versus 231.5 (131.0-408.5) ng/mL, P = 0.55] and troponin-I [128.5 (63.5-227.8) versus 109.0 (43.8-220.0) ng/mL, P = 0.52) ] did not differ between the darbepoetin-α and control group. Fifty-seven patients completed the baseline and 4-month follow-up CMR. There were no differences in infarct size [30.6 (18.1-49.8) versus 31.5 (22.5-47.3) cm³, P = 0.91), proportion of salvaged myocardium [26.7% (15.9-42.6%) versus 35.8% (22.4-48.8%), P = 0.12) or PIR (8.0% versus 6.7%, P = 0.62) between the two groups. Composite cardiovascular outcomes did not differ between the two groups.In conclusion, administration of intracoronary darbepoetin-α before reperfusion did not reduce infarct size or post-infarct remodeling in STEMI patients.

Evaluation of embolic deflection device using optical particle tracking

Trans-aortic valve replacement is a new endovascular procedure which has started to be used routinely in cardiac interventional suites. During such procedures a stent-like device containing new aortic valves is placed over the damaged ones, possibly causing calcifications to be dislodged and released in arteries leading to stroke. To prevent such events, new devices are being developed to provide distal protection to the brain supplying arteries. Currently there is a need to evaluate such device efficacy in a repeatable manner. We are proposing and investigating such a method based on particle optical tracking. We simulated such protective devices using two porous screens (150 and 200 μm pore size) which were placed in an arterial bifurcation phantom connected to a clinically relevant flow loop. A mask was acquired and gold embolic particles (100-300μm) were injected at a steady rate using a motorized injector. Optical images with 2 ms exposure were acquired at 30 fps. Images were subtracted, thresholded and filtered using a 5×5 median filter. ROI's were drawn over the main and bifurcating arteries and a particle counting algorithm was used to estimate particle flow rates in each artery for each run. The unprotected and the two protected cases were evaluated. Before filter placement, the particle flow rate was 60 and 40 %, respectively, of the main artery. After the filter placement, the particle flow rate in the protected branch was 4% and 8% of the particle flow rate in the main artery. We present a method to assess the efficacy of such devices using an optical particle tracking and counting technique.