Serum Cardiac Troponin I Concentration in Dogs with Precapillary and Postcapillary Pulmonary Hypertension

Background: Pulmonary hypertension (PH) is a disease condition leading to right-sided cardiac hypertrophy and, eventually,right-sided heart failure. Cardiac troponin I (cTnI) is a circulating biomarker of cardiac damage.Hypothesis: Myocardial damage can occur in dogs with precapillary and postcapillary PH.Animals: One hundred and thirty-three dogs were examined: 26 healthy controls, 42 dogs with mitral valve disease (MVD)without PH, 48 dogs with pulmonary hypertension associated with mitral valve disease (PH-MVD), and 17 dogs with precapillaryPH.Methods: Prospective, observational study. Serum cTnI concentration was measured with a commercially availableimmunoassay and results were compared between groups.Results: Median cTnI was 0.10 ng/mL (range 0.10–0.17 ng/mL) in healthy dogs. Compared with the healthy population,median serum cTnI concentration was increased in dogs with precapillary PH (0.25 ng/mL; range 0.10–1.9 ng/mL; P o .001)and in dogs with PH-MVD (0.21 ng/mL; range 0.10–2.10 ng/mL; P o .001). Median serum cTnI concentration of dogs withMVD (0.12 ng/mL; range 0.10–1.00 ng/mL) was not significantly different compared with control group and dogs with PHMVD.In dogs with MVD and PH-MVD, only the subgroup with decompensated PH-MVD had significantly higher cTnIconcentration compared with dogs with compensated MVD and PH-MVD. Serum cTnI concentration showed significantmodest positive correlations with the calculated pulmonary artery systolic pressure in dogs with PH and some echocardiographicindices in dogs with MVD and PH-MVD.Conclusions and Clinical Importance: Serum cTnI is high in dogs with either precapillary and postcapillary PH. Myocardialdamage in dogs with postcapillary PH is likely the consequence of increased severity of MVD.[...]