Inside ST-elevation myocardial infarction by monitoring concentrations of cardiovascular risk biomarkers in blood

Timing of SGLT2i initiation after acute myocardial infarction

BACKGROUND

Pharmacological post-MI treatment is routinely initiated at intensive/cardiac care units. However, solid evidence for an early start of these therapies is only available for dual platelet therapy and statins, whereas data on beta blockers and RAAS inhibitors are heterogenous and mainly limited to STEMI and heart failure patients. Recently, the EMMY trial provided the first evidence on the beneficial effects of SGLT2 inhibitors (SGLT2i) when initiated early after PCI. In patients with type 2 diabetes mellitus, SGLT2i are considered "sick days drugs" and it, therefore, remains unclear if very early SGLT2i initiation following MI is as safe and effective as delayed initiation.

METHODS AND RESULTS

The EMMY trial evaluated the effect of empagliflozin on NT-proBNP and functional and structural measurements. Within the Empagliflozin group, 22 (9.5%) received early treatment (< 24 h after PCI), 98 (42.2%) within a 24 to < 48 h window (intermediate), and 111 (48.1%) between 48 and 72 h (late). NT-proBNP levels declined by 63.5% (95%CI: - 69.1; - 48.1) in the early group compared to 61.0% (- 76.0; - 41.4) in the intermediate and 61.9% (- 70.8; - 45.7) in the late group (n.s.) within the Empagliflozin group with no significant treatment groups-initiation time interaction (pint = 0.96). Secondary endpoints of left ventricular function (LV-EF, e/e`) as well as structure (LVESD and LVEDD) were also comparable between the groups. No significant difference in severe adverse event rate between the initiation time groups was detected.

CONCLUSION

Very early administration of SGLT2i after acute myocardial infarction does not show disadvantageous signals with respect to safety and appears to be as effective in reducing NT-proBNP as well as improving structural and functional LV markers as initiation after 2-3 days.

Neprilysin levels at the acute phase of ST-elevation myocardial infarction

BACKGROUND

Several preliminary analyses suggested an association between neprilysin (NEP) levels and myocardial infarction.

HYPOTHESIS

The objective was to assess whether NEP plasma levels following reperfusion might be a surrogate for infarct size (IS) or predict adverse outcomes in acute ST-segment elevation myocardial infarction (STEMI) patients.

METHODS

We measured NEP levels in a prospective cohort of 203 patients with STEMI referred for primary percutaneous coronary intervention. Circulating soluble NEP was measured by enzyme-linked immunosorbent assay at admission (t0) and 4 hours later (t4) following reperfusion and on 7 times points (t0, t4, t12, t24, t48, day 7 and day 30) in a subset of 21 patients. IS and left ventricular ejection fraction (LVEF) were measured at 1 month by cardiac magnetic resonance. Adverse cardiovascular outcomes were collected at 12-month follow-up.

RESULTS

Median t0 and t4 NEP levels in 203 patients were respectively 88.3 pg/mL (interquartile range [IQR] [14; 375.4]) and 101.5 pg/mL (IQR [18.5; 423.8]). These levels remained unchanged over 1 month (P = 0.70). NEP levels did not correlate significantly with IS (P = 0.51) or LVEF (P = 0.34). There was no correlation between NEP and troponin, creatine kinase and interleukin-6 levels at h0 and h4. NEP levels above the median were not associated with adverse outcomes at follow-up (hazard ratio = 1.28, 95% confidence interval [0.69; 2.37]; P = 0.42).

CONCLUSIONS

NEP serum levels were widely distributed and did not change significantly in the first hours and 1-month period following reperfusion in STEMI patients. There was no significant relationship with markers of infarct size and inflammation, and 1-year adverse outcomes.

A multi-site coronary sampling study on CRP in non-STEMI: Novel insights into the inflammatory process in acute coronary syndromes

BACKGROUND AND AIMS

Inflammation has become a key element in cardiovascular disease, and recently, new anti-inflammatory interventions have shown promising results. In this context, CRP levels have been thoroughly studied in vitro and in animals, but studies in humans are scarce and insights into its release, site(s) of production and uptake are not uniform.

METHODS

We performed a biomarker study with multi-site sampling in the coronary circulation, in non-ST elevation MI (NSTEMI) patients with coronary angiography and right-sided catheterisation. Trans-lesional gradients were obtained by sampling distal to the culprit lesion, in patients with a suitable anatomy. To asses trans-cardiac gradients, blood was sampled from the systemic circulation, coronary sinus (CS) and great cardiac vein. Concentrations of CRP were measured with a high-sensitivity assay.

RESULTS

In 42 patients, a median systemic venous CRP concentration of 4.97 mg/L was observed. There was no evidence of a trans-lesional gradient (4.59 mg/L versus 4.56 mg/L, p = 0.278; n = 14). A significant decrease in CRP concentration was observed between systemic arterial and CS samples (4.88 mg/L versus 4.44 mg/L; p < 0.001; n = 42). This trans-cardiac gradient was irrespective of time of presentation, infarct size and culprit lesion location. The gradient was not only driven by blood that ran through the injured myocardium, but also by lower CRP concentrations in the coronary veins that drain non-infarcted myocardium.

CONCLUSIONS

In the context of NSTEMI, we observed a trans-cardiac decrease in CRP, which may indicate the first human in vivo proof of a net CRP uptake by the myocardium, with a role for CRP both in the injured and adjacent myocardium.

Plasma Catestatin in Patients with Acute Coronary Syndrome

OBJECTIVES

To measure plasma catestatin levels in patients with acute coronary syndrome and investigate whether there is an association between catestatin levels and long-term outcome.

METHODS

Patients (n = 170) with suspected acute coronary syndrome who underwent emergency coronary angiography were enrolled, including 46 with acute ST-segment elevation myocardial infarction (STEMI), 89 with unstable angina pectoris (UAP), and 35 without coronary artery disease (CAD). All patients were followed for 2 years to measure the occurrence of major adverse cardiovascular events (MACEs), including death from a cardiovascular cause, recurrent acute myocardial infarction, or hospital admission for heart failure or revascularization.

RESULTS

On average, the plasma catestatin levels in patients with STEMI (0.80 ± 0.62 ng/ml) and UAP (0.99 ± 0.63 ng/ml) were significantly lower than the levels seen in the control group with no evidence of CAD (1.38 ± 0.98 ng/ml; p = 0.001). In multivariable linear regression, body mass index, presence of hypertension, and type of CAD were independently related to the plasma catestatin level. However, there were no significant differences in MACEs between patients with high and low levels of catestatin.

CONCLUSIONS

The plasma catestatin levels in patients with STEMI and UAP were lower than the levels seen in patients without CAD.

Typical rise and fall of troponin in (peri-procedural) myocardial infarction: A systematic review

AIM: To identify the typical shape of the rise and fall curve of troponin (Tn) following the different types of myocardial infarction (MI).

METHODS: We conducted a systematic search in PubMed and Embase including all studies which focused on the kinetics of Tn in MI type 1, type 4 and type 5. Tn levels were standardized using the 99^th percentile, a pooled mean with 95%CI was calculated from the weighted means for each time point until 72 h.

RESULTS: A total of 34 of the 2528 studies identified in the systematic search were included. The maximum peak level of the Tn was seen after 6 h after successful reperfusion of an acute MI, after 12 h for type 1 MI and after 72 h for type 5 MI. In type 1 MI there were additional smaller peaks at 1 h and at 24 h. After successful reperfusion of an acute MI there was a second peak at 24 h. There was not enough data available to analyze the Tn release after MI associated with percutaneous coronary intervention (type 4).

CONCLUSION: The typical rise and fall of Tn is different for type 1 MI, successful reperfusion of an acute MI and type 5 MI, with different timing of the peak levels and different slopes of the fall phase.

Oxytocin ameliorates the immediate myocardial injury in heart transplant through down regulation of the neutrophil dependent myocardial apoptosis

Cardiac oxytocin (OT) is structurally identical to that found in the hypothalamus, which thereby indicates that cardiac OT is derived from the same gene and is an active form of OT. The abundance of OT and OT receptors in atrial myocytes shows that, directly and/or via the release of the cardiac hormone atrial natriuretic peptide, OT can regulate the force of cardiac contractions. Previous studies have demonstrated the role of OT in the myocardial inflammatory response. The mechanism by which OT elicits protective myocardial effects in the immediate post-transplantation period is not yet clear, and the role of the early phase inflammatory elements in this mechanism has not yet been studied. As a result, in this study, we have investigated the anti-inflammatory effects of OT on myocardial protection in the immediate post-transplantation period.

Oxytocin ameliorates the immediate myocardial injury in rat heart transplant through downregulation of neutrophil-dependent myocardial apoptosis

BACKGROUND

Cardiac oxytocin (OT) is structurally identical to that found in the hypothalamus, indicating that this active form of OT is derived from the same gene. The abundance of OT and its receptors in atrial myocytes suggests that, directly and/or via the release of the cardiac hormone atrial natriuretic peptide, this hormone regulates the force of cardiac contractions. Previous studies have demonstrated a role of OT in myocardial inflammatory responses. We sought to study protective myocardial and anti-inflammatory effects of OT in the immediate post-transplant period.

METHODS

We grouped adult male Albino rats into sham, control, and OT-treated groups. Control and treated groups underwent heterotopic cervical heart transplantation. Myocardial injury was assessed by measuring plasma cardiac troponin I, and myocardial proinflammatory cytokines as well as by performing histopathologic assessments injury score, and of apoptotic degree. Myocardial myeloperoxidase, neutrophil infiltration, neutrophil chemotactic mediators as well as formation of reactive oxygen and reactive nitrogen species were measured in the myocardium at 3 hours after reperfusion to assess neutrophil-dependent myocardial injury.

RESULTS

OT downregulates neutrophil chemotactic molecules--KC/CXCL1 and MIP-2/CXCL2. The decrement in myocardial PMN infiltration was associated with reduced reactive oxygen and reactive nitrogen species formation in the myocardium at 3 hours after reperfusion following global ischemia. OT reduced postmyocardial ischemia/reperfusion apoptotic processed.

CONCLUSION

OT ameliorated immediate myocardial injury in heart grafts, through downregulation of the inflammatory response, of reactive oxygen species, and of neutrophil dependent apoptosis.

Release kinetics of circulating cardiac myosin binding protein-C following cardiac injury

Diagnosis of myocardial infarction (MI) is based on ST-segment elevation on electrocardiographic evaluation and/or elevated plasma cardiac troponin (cTn) levels. However, troponins lack the sensitivity required to detect the onset of MI at its earliest stages. Therefore, to confirm its viability as an ultra-early biomarker of MI, this study investigates the release kinetics of cardiac myosin binding protein-C (cMyBP-C) in a porcine model of MI and in two human cohorts. Release kinetics of cMyBP-C were determined in a porcine model of MI (n = 6, pigs, either sex) by measuring plasma cMyBP-C level serially from 30 min to 14 days after coronary occlusion, with use of a custom-made immunoassay. cMyBP-C plasma levels were increased from baseline (76 ± 68 ng/l) at 3 h (767 ± 211 ng/l) and peaked at 6 h (2,418 ± 780 ng/l) after coronary ligation. Plasma cTnI, cTnT, and myosin light chain-3 levels were all increased 6 h after ligation. In a cohort of patients (n = 12) with hypertrophic obstructive cardiomyopathy undergoing transcoronary ablation of septal hypertrophy, cMyBP-C was significantly increased from baseline (49 ± 23 ng/l) in a time-dependent manner, peaking at 4 h (560 ± 273 ng/l). In a cohort of patients with non-ST segment elevation MI (n = 176) from the SYNERGY trial, cMyBP-C serum levels were significantly higher (7,615 ± 4,514 ng/l) than those in a control cohort (416 ± 104 ng/l; n = 153). cMyBP-C is released in the blood rapidly after cardiac damage and therefore has the potential to positively mark the onset of MI.

Multi-marker network in ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention: when and what to measure

BACKGROUND

Data on the correlations between biomarkers to suggest cost-effective multi-marker (MM) panels predictive for ST-elevation myocardial infarction (STEMI) patients are lacking. We sought to explore the relationship between cardiac troponin I (cTnI), C-reactive protein (CRP), B-type natriuretic peptide (BNP), and chromogranin A (CgA) accounting for biomarkers' profiles detected within 48h from successful primary percutaneous coronary intervention (PPCI).

METHODS

In 73 STEMI patients cTnI, CRP, BNP, and CgA were measured before PPCI and 6, 24, and 48h later. STATIS methods generalizing Principal Component Analysis on three-way data sets were employed to extract information about: 1) similarities between patients, 2) contribution of each time of sampling and 3) correlations between biomarkers' profiles.

RESULTS

STEMI patients who underwent successful PPCI emerged to have a homogeneous profile tailored on biomarkers' evaluation within 48h. Their measurements at 24h contributed the most variability and information both to patients' and to biomarkers' profiles. BNP and cTnI were highly correlated and explained the 40.1% of the total variance, whereas CgA resulted independent and explained the 26.3% of the total variance.

CONCLUSIONS

Markers' measurements at 24h after PPCI contributed most information to the definition of patients' profile. BNP and cTnI resulted interchangeable in a MM panel for reporting about the extent of necrosis.