Relationship between blood viscosity and no-reflow phenomenon in ST-segment elevation myocardial infarction performed in primary percutaneous coronary interventions

SGLT1 contributes to glucose-mediated exacerbation of ischemia-reperfusion injury in ex vivo rat heart

Hyperglycaemia is common during acute coronary syndromes (ACS) irrespective of diabetic status and portends excess infarct size and mortality, but the mechanisms underlying this effect are poorly understood. We hypothesized that sodium/glucose linked transporter-1 (SGLT1) might contribute to the effect of high-glucose during ACS and examined this using an ex-vivo rodent heart model of ischaemia-reperfusion injury. Langendorff-perfused rat hearts were subjected to 35 min ischemia and 2 h reperfusion, with variable glucose and reciprocal mannitol given during reperfusion in the presence of pharmacological inhibitors of SGLT1. Myocardial SGLT1 expression was determined in rat by rtPCR, RNAscope and immunohistochemistry, as well as in human by single-cell transcriptomic analysis. High glucose in non-diabetic rat heart exacerbated reperfusion injury, significantly increasing infarct size from 45 ± 3 to 65 ± 4% at 11-22 mmol/L glucose, respectively (p < 0.01), an association absent in diabetic heart (32 ± 1-37 ± 5%, p = NS). Rat heart expressed SGLT1 RNA and protein in vascular endothelium and cardiomyocytes, with similar expression found in human myocardium by single-nucleus RNA-sequencing. Rat SGLT1 expression was significantly reduced in diabetic versus non-diabetic heart (0.608 ± 0.08 compared with 1.116 ± 0.13 probe/nuclei, p < 0.01). Pharmacological inhibitors phlorizin, canagliflozin or mizagliflozoin in non-diabetic heart revealed that blockade of SGLT1 but not SGLT2, abrogated glucose-mediated excess reperfusion injury. Elevated glucose is injurious to the rat heart during reperfusion, exacerbating myocardial infarction in non-diabetic heart, whereas the diabetic heart is resistant to raised glucose, a finding which may be explained by lower myocardial SGLT1 expression. SGLT1 is expressed in vascular endothelium and cardiomyocytes and inhibiting SGLT1 abrogates excess glucose-mediated infarction. These data highlight SGLT1 as a potential clinical translational target to improve morbidity/mortality outcomes in hyperglycemic ACS patients.

The predictive value of laboratory parameters for no-reflow phenomenon in patients with ST-elevation myocardial infarction following primary percutaneous coronary intervention: A meta-analysis

To date, the predictive role of laboratory indicators for the phenomenon of no flow is unclear. Hence, our objective was to conduct a meta-analysis to investigate the association between laboratory parameters and the risk of the no-reflow phenomenon in patients with ST-elevation myocardial infarction (STEMI) following primary percutaneous coronary intervention (PCI). This, in turn, aims to offer valuable insights for early clinical prediction of no-reflow. We searched Pubmed, Embase, and Cochrane Library from the establishment of the database to October 2023. We included case-control or cohort study that patients with STEMI following primary PCI. We excluded repeated publication, research without full text, incomplete information or inability to conduct data extraction and animal experiments, reviews, and systematic reviews. STATA 15.1 was used to analyze the data. The pooled results indicated that elevated white blood cell (WBC) count (odds ratio [OR] = 1.061, 95% confidence interval [CI]: 1.013-1.112), neutrophil count (OR = 1.324, 95% CI: 1.128-1.553), platelet (PLT) (OR = 1.002, 95% CI: 1.000-1.005), blood glucose (OR = 1.005, 95% CI: 1.002-1.009), creatinine (OR = 1.290, 95% CI: 1.070-1.555), total cholesterol (TC) (OR = 1.022, 95% CI: 1.012-1.032), d-dimer (OR = 1.002, 95% CI: 1.001-1.004), and fibrinogen (OR = 1.010, 95% CI: 1.005-1.015) were significantly associated with increased risk of no-reflow. However, elevated hemoglobin was significantly associated with decreased risk of no-reflow. In conclusion, our comprehensive analysis highlights the predictive potential of various parameters in assessing the risk of no-reflow among STEMI patients undergoing PCI. Specifically, WBC count, neutrophil count, PLT, blood glucose, hemoglobin, creatinine, TC,  d-dimer, and fibrinogen emerged as significant predictors. This refined risk prediction may guide clinical decision-making, allowing for more targeted and effective preventive measures to mitigate the occurrence of no-reflow in this patient population.

Relationship between blood viscosity and thrombus burden in ST-segment elevation myocardial infarction

BACKGROUND

İncreased whole blood viscosity (WBV) is associated with increased infarct area, impaired microvascular circulation and mortality in patients with ST-elevation myocardial infarction (STEMI).

OBJECTIVES

We aimed to analyze the association between the WBV and thrombus burden (TB) in STEMI patients.

METHODS

This cross-sectional study included 167 STEMI patients who received primary percutaneous coronary intervention. WBV values were assessed using hematocrit and total protein values, and low shear rate(LSR) and high shear rate(HSR) were calculated. Angiographic TB was assessed according to the definition of the Thrombolysis in Myocardial Infarction (TIMI) study group. The cases were dichotomized into low TB (grade 1-3) (n = 87) and high TB (grade 4-5) (n = 80) groups.

RESULTS

The mean HSR and LSR values of the high TB group were significantly increased compared to the low TB group (p < 0.001, for each). In ROC analysis,for prediction of TB, a cut-off value of 3.83 WBV for HSR had a 71% sensitivity and a 60.7% specificity, and a cut-off value of 21 WBV for LSR had a 70% sensitivity and 59.9% specificity (p < 0.001,for each). Multivariate regression analysis showed that both HSR (OR = 2.408;p=0.020) and LSR (OR = 1.055;p=0.021) were independent predictors for high TB.

CONCLUSION

İncreased WBV was an independent predictor for the presence of high TB in patients with STEMI.

The predictive value of MAPH score for determining thrombus burden in patients with non-ST segment elevation myocardial infarction

Background

A high thrombus burden has been connected with poor clinical events in patients with non-ST segment elevation myocardial infarction (NSTEMI). In patients with STEMI, a high MAPH score has been associated with a large thrombus burden. However, the predictive value of the MAPH score in determining the thrombus burden in patients with NSTEMI is unclear. The present report aimed to evaluate the prognostic role of the MAPH score in the estimating coronary thrombus burden in NSTEMI patients. The study patients were split into two groups according to their thrombus grade. The low shear rate (LSR) and high shear rate (HSR) were estimated by haematocrit levels and serum total protein levels. The MAPH score was calculated by adding mean platelet volume (MPV) levels and age, in addition to total protein and haematocrit.

Results

The patients with a high thrombus burden (HTB) had a higher LSR, higher HSR and higher MAPH score compared to patients with low thrombus burden. MAPH score was found to be an independent predictors of HTB in Model 1 (OR: 1.124, 95% CI: 1.011–1.536; p = 0.039) and Model 2 (OR: 1.236; 95% CI: 1.002–1.525; p = 0.047). The cut-off value of the MAPH score for predicting HTB was 2 based on the Youden index.

Conclusions

The MAPH score, which calculated by adding MPV levels and age, in addition to total protein and haematocrit, is a novel, easily accessible score. The MAPH score at both LSR and HSR was an independent predictor of HTB.

A New Score for Determining Thrombus Burden in STEMI Patients: The MAPH Score

Aim

to investigate whether the MAPH score, which is a new score that combines blood viscosity biomarkers such as mean platelet volume (MPV), total protein and hematocrit, can be used to predict thrombus burden in ST-segment elevation myocardial infarction (STEMI) patients.

Methods

A total of 473 consecutive patients with STEMI were included in the study. Intracoronary tirofiban/abciximab infusion was applied to patients with thrombus load ≥3 and these patients (n = 71) were defined as the patient group with high thrombus load. MPV, age, hematocrit and total protein values of the patients were recorded. High shear rate (HSR) and low shear rate (LSR) were calculated from total protein and hematocrit values. Cut-off values were determined for high thrombus load by using Youden index, and score was determined as 0 or 1 according to cut-offs. The sum of the scores was calculated as the MAPH score.

Results

The mean age of the patients included in the study was 59.6 ± 12.6 (n = 354 male, 74.8%). There was no difference between the groups in terms of gender, HT and DM (P = .127, P = .402 and P = .576, respectively). In the group with high thrombus load; total protein, MPV and hematocrit values were higher (P < .001, P = .001 and P = .03, respectively). Comparison of receiver operating characteristic (ROC) curve analysis revealed that the MAPH score had better performance in predicting higher thrombus load than both other self-containing parameters and HSR and LSR.

Conclusion

The MAPH score may be a new score that can be used to determine thrombus burden in STEMI patients.