High-throughput targeted proteomics discovery approach and spontaneous reperfusion in ST-segment elevation myocardial infarction

BACKGROUND

Although spontaneous reperfusion (SR) prior to primary percutaneous coronary intervention (pPCI) is associated with improved outcomes, its pathophysiology remains unclear. The objective of the study was to explore associations between SR in ST-segment elevation myocardial infarction (STEMI) using a multimarker cardiovascular proteins strategy METHODS: We evaluated STEMI patients from the Assessment of Pexelizumab in Acute Myocardial Infarction trial treated with pPCI within 6 hours from symptom onset. SR was core laboratory-defined as pre-PCI Thrombolysis in Myocardial Infarction flow 2 or 3. Ninety-one cardiovascular disease-related serum biomarkers drawn prior to PCI were analyzed using a high-throughput "targeted discovery" panel. Expression levels for individual biomarkers were compared between patients with/without SR. A hierarchical clustering method of biomarkers identified clusters of biomarkers that differentiated the 2 groups. Associations between individual biomarkers and clusters with SR were further evaluated by multivariable logistic regression.

RESULTS

Of 683 patients studied, 290 had spontaneous reperfusion; those with compared to without SR were more likely noninferior STEMI and had lower clinical acuity and lower baseline levels of troponin and creatine kinase. SR was associated with a lower occurrence of 90-day composite of death, heart failure, or cardiogenic shock. Fifty-two of 91 individual biomarkers were significantly univariably associated with SR. Forty-five remained significant with adjustment for false discovery rate. Using cluster analysis, 26 biomarkers clusters were identified, explaining 72% of total covariance, and 13 biomarker clusters were significantly associated with SR after multivariable adjustment. SR was associated with higher mean expression levels of proteins in all 13 clusters. The cluster most strongly associated with SR consisted of novel proteins across various distinct, yet interlinked, pathobiological processes (kallikrein-6, matrix extracellular phosphoglycoprotein, matrix mettaloproteinaise-3, and elafin).

CONCLUSIONS

Spontaneous reperfusion prior to pPCI in STEMI was associated with a lower risk of adverse clinical events. These exploratory data from a targeted discovery proteomics platform identifies novel proteins across diverse, yet complementary, pathobiological axes that show promise in providing mechanistic insights into spontaneous reperfusion in STEMI.

CONDENSED ABSTRACT

Spontaneous reperfusion has been established with improved STEMI outcomes, yet its pathobiology is unclear and appears to involve diverse physiological processes. Using a 91-biomarker high-throughput proteomics platform, we studied 683 STEMI patients in the APEX AMI trial (290 had core laboratory-adjudicated pre-PCI TIMI 2/3 flow) and identified 52 proteins that univariably associate with spontaneous reperfusion. Cluster analysis identified 26 biomarker clusters (explaining 72% of total variance), 13 of which, after multivariable adjustment, were significantly associated with spontaneous reperfusion. Four proteins (kallikrein-6, matrix extracellular phosphoglycoprotein, matrix mettaloproteinaise-3, and elafin) across diverse, yet complementary, pathways appear to be associated most strongly with spontaneous reperfusion.

Admission hyperglycemia is associated with failed reperfusion following fibrinolytic therapy in patients with STEMI: results of a retrospective study

BACKGROUND

Hyperglycemia on admission is associated with increased mortality rates in patients with ST-elevation myocardial infarction (STEMI) who are treated with either fibrinolytic therapy (FT) or primary percutaneous coronary intervention (PCI). However, data regarding the relationship between hyperglycemia and the success of FT are lacking. The aim of this study was to investigate the value of admission blood glucose for the prediction of failed reperfusion following FT.

METHODS AND RESULTS

This is a retrospective study of 304 STEMI patients who received FT and whose admission glucose levels were recorded. The main outcome measure was ST segment resolution≥50%. The median (interquartile range [IQR]) blood glucose level in the entire study group was 112 (95-153). In 92 (30.2%) patients, FT was unsuccessful and rescue PCI was performed. Admission glucose (126 [99-192] vs. 110 [94-144] mg/dL, p<0.001), time from symptom onset to FT (180 [120-270] vs. 150 [120-180] min, p=0.009), and maximum ST elevation amplitude (3 [2-7] vs. 3 [2-6] mm, p=0.05) were higher in the failed reperfusion group than in the reperfusion group. Admission hyperglycemia was an independent predictive factor for failed reperfusion (hazard ratio 4.79 [1.80-12.76], p=0.002), along with time from symptom onset to fibrinolysis and anterior wall myocardial infarction.

CONCLUSIONS

In patients with STEMI who undergo FT, admission hyperglycemia is an independent predictor of the failure of fibrinolysis.