High Circulating Dipeptidyl Peptidase 3 Predicts Mortality and Need for Organ Support in Cardiogenic Shock: An Ancillary Analysis of the ACCOST-HH Trial.

BACKGROUND: Cardiogenic shock (CS) is burdened with high mortality. Efforts to improve outcome are hampered by the difficulty of individual risk stratification and the lack of targetable pathways. Previous studies demonstrated that elevated circulating dipeptidyl peptidase 3 (cDPP3) is an early predictor of short-term outcome in CS, mostly of ischemic origin. Our objective was to investigate the association between cDPP3 and short-term outcomes in a diverse population of patients with CS. METHODS AND RESULTS: cDPP3 was measured at baseline and after 72 hours in the AdreCizumab against plaCebO in SubjecTs witH cardiogenic sHock (ACCOST-HH) trial. The association of cDPP3 with 30-day mortality and need for organ support was assessed. Median cDPP3 concentration at baseline was 43.2 ng/mL (95% confidence interval [CI], 21.2-74.0 ng/mL) and 77 of the 150 patients (52%) had high cDPP3 over the predefined cutoff of 40 ng/mL. Elevated cDPP3 was associated with higher 30-day mortality (adjusted hazard ratio [aHR] = 1.7; 95% CI, 1.0-2.9), fewer days alive without cardiovascular support (aHR, 3 days [95% CI, 0-24 days] vs aHR, 21 days [95% CI, 5-26 days]; P < .0001) and a greater need for renal replacement therapy (56% vs 22%; P < .0001) and mechanical ventilation (90 vs 74%; P = .04). Patients with a sustained high cDPP3 had a poor prognosis (reference group). In contrast, patients with an initially high but decreasing cDPP3 at 72 hours had markedly lower 30-day mortality (aHR, 0.17; 95% CI, 0.084-0.34), comparable with patients with a sustained low cDPP3 (aHR, 0.23; 95% CI, 0.12-0.41). The need for organ support was markedly decreased in subpopulations with sustained low or decreasing cDPP3. CONCLUSIONS: The present study confirms the prognostic value of cDPP3 in a contemporary population of patients with CS.

Circulating Dipeptidyl Peptidase 3 Modulates Systemic and Renal Hemodynamics Through Cleavage of Angiotensin Peptides.

BACKGROUND: High circulating DPP3 (dipeptidyl peptidase 3) has been associated with poor prognosis in critically ill patients with circulatory failure. In such situation, DPP3 could play a pathological role, putatively via an excessive angiotensin peptides cleavage. Our objective was to investigate the hemodynamics changes induced by DPP3 in mice and the relation between the observed effects and renin-angiotensin system modulation. METHODS: Ten-week-old male C57Bl/6J mice were subjected to intravenous injection of purified human DPP3 or an anti-DPP3 antibody (procizumab). Invasive blood pressure and renal blood flow were monitored throughout the experiments. Circulating angiotensin peptides and catecholamines were measured and receptor blocking experiment performed to investigate the underlying mechanisms. RESULTS: DPP3 administration significantly increased renal blood flow, while blood pressure was minimally affected. Conversely, procizumab led to significantly decreased renal blood flow. Angiotensin peptides measurement and an AT1R (angiotensin II receptor type 1) blockade experiment using valsartan demonstrated that the renovascular effect induced by DPP3 is due to reduced AT1R activation via decreased concentrations of circulating angiotensin II, III, and IV. Measurements of circulating catecholamines and an adrenergic receptor blockade by labetalol demonstrated a concomitant catecholamines release that explains blood pressure maintenance upon DPP3 administration. CONCLUSIONS: High circulating DPP3 increases renal blood flow due to reduced AT1R activation via decreased concentrations of circulating angiotensin peptides while blood pressure is maintained by concomitant endogenous catecholamines release.

Regional protein expression changes within the left ventricle in a mouse model of dyssynchronous and resynchronized heart failure.

AIMS: The biological mechanisms conveying the salutary effects of cardiac resynchronization therapy in heart failure remain elusive. We have recently developed a mouse model of heart failure with dyssynchrony/resynchronization. The aim of this study was to characterize regional left ventricular heterogeneity in protein expression comparing early (septum) and late (lateral) activated left ventricular wall segments in synchronous (SHF), dyssynchronous (DHF), and resynchronized heart failure (RHF). METHODS AND RESULTS: Mice subjected to ischaemia/reperfusion were divided into three groups: sinus rhythm for 4 weeks (SHF), right ventricular pacing for 4 weeks (DHF), and right ventricular pacing for 2 weeks and 2 weeks of sinus rhythm (RHF). Relative concentrations of 92 proteins from septal and lateral left ventricular wall segments (n = 10 per group) were compared within each group. We also analysed the effect of DHF vs. SHF and RHF vs. DHF on protein expression pattern comparing the same left ventricular segments between the groups. Proteins with significantly differential expression between left ventricular segments were analysed for protein-protein correlations, protein-protein interactions, and biological and signalling pathways. Eight proteins were significantly down-regulated in the late activated (compared with early activated) lateral wall uniquely in RHF (P < 0.05 adjusted for a 5% false discovery rate): Erbb4, Ntf3, Pdgfb, Tnf, Notch3, Qdpr, Tpp1, and Itgb6. Protein correlation matrix showed that six of these were strongly and positively correlated and five had known protein-protein interactions. Biological pathways mainly down-regulated in late activated myocardium in RHF were MAPK signalling and hypertrophic cardiomyopathy. There were no significantly differentially expressed proteins comparing the same left ventricular segments between the DHF and SHF (range of P-values: 0.05-1.00) and RHF and DHF (range of P-values: 0.32-1.00). CONCLUSIONS: In a mouse model of heart failure with dyssynchrony and resynchronization, we observed down-regulation of several proteins in the late activated lateral wall, compared with the septum, in resynchronized mice. These proteins display significant protein-protein correlation and share biological signalling pathways, including MAPK activation and hypertrophy signalling.