Utility of B-Type Natriuretic Peptide and Troponin in Predicting Outcomes in Peripartum Cardiomyopathy

Background: Biomarkers such as B-type natriuretic peptide (BNP) and cardiac troponin (cT) have prognostic significance in the general heart failure (HF) population, yet their utility in predicting outcomes in peripartum cardiomyopathy (PPCM) is not fully understood. Methods: A clinical database from 20 hospitals in Utah and Idaho was queried for all patients with an index admission for PPCM between November 2003 and March 2008. The effect of serum BNP and cT drawn nearest to the index admission was assessed in relation to readmissions and mortality using Kaplan Meier analysis and age-adjusted Cox proportional hazards analysis. The impact of BNP<100 pg/dL and ≥ 100 pg/dL; and cT<0.4 ng/mL and ≥ 0.4 ng/mL was evaluated. Results: We identified 117 patients with PPCM. Average age was 30.5 ± 7.2 years, and follow-up time 1.8 ±1.3 years (range 0.1–3.6 years). Two patients died (mortality rate 1.7% or 0.94%/year), and 40 patients (34%) per year were readmitted to the hospital. In the 98 patients who had a BNP measured, the mean was 705.1 pg/mL ± 721.2 (range 0–3500 pg/mL). Seventy patients had a BNP assessed within 10 days, and 77 within 30 days, of their index HF admission. BNP ≥ 100 was not found to correlate with readmissions or mortality (p=0.32). The BNP of the patients who died were 3005 pg/dL (one value found) and 32, 701, 395 (3 values found). Thirty nine patients had a cT at their index admission, with a mean value of 1.07 (2.89 standard deviation). When comparing readmissions/mortality, there were no differences between the group having a cT<0.4 ng/mL vs. those with a cT ≥ 0.4 ng/mL (p=0.42). Conclusions: While both BNP and cT are likely to be elevated in women hospitalized with PPCM, an elevated BNP or cT at the index HF admission does not predict subsequent readmissions or mortality. When comparing PPCM to other cardiomyopathies, biomarkers may not be as prognostically useful. Further study is warranted in a larger population. Background: Biomarkers such as B-type natriuretic peptide (BNP) and cardiac troponin (cT) have prognostic significance in the general heart failure (HF) population, yet their utility in predicting outcomes in peripartum cardiomyopathy (PPCM) is not fully understood. Methods: A clinical database from 20 hospitals in Utah and Idaho was queried for all patients with an index admission for PPCM between November 2003 and March 2008. The effect of serum BNP and cT drawn nearest to the index admission was assessed in relation to readmissions and mortality using Kaplan Meier analysis and age-adjusted Cox proportional hazards analysis. The impact of BNP<100 pg/dL and ≥ 100 pg/dL; and cT<0.4 ng/mL and ≥ 0.4 ng/mL was evaluated. Results: We identified 117 patients with PPCM. Average age was 30.5 ± 7.2 years, and follow-up time 1.8 ±1.3 years (range 0.1–3.6 years). Two patients died (mortality rate 1.7% or 0.94%/year), and 40 patients (34%) per year were readmitted to the hospital. In the 98 patients who had a BNP measured, the mean was 705.1 pg/mL ± 721.2 (range 0–3500 pg/mL). Seventy patients had a BNP assessed within 10 days, and 77 within 30 days, of their index HF admission. BNP ≥ 100 was not found to correlate with readmissions or mortality (p=0.32). The BNP of the patients who died were 3005 pg/dL (one value found) and 32, 701, 395 (3 values found). Thirty nine patients had a cT at their index admission, with a mean value of 1.07 (2.89 standard deviation). When comparing readmissions/mortality, there were no differences between the group having a cT<0.4 ng/mL vs. those with a cT ≥ 0.4 ng/mL (p=0.42). Conclusions: While both BNP and cT are likely to be elevated in women hospitalized with PPCM, an elevated BNP or cT at the index HF admission does not predict subsequent readmissions or mortality. When comparing PPCM to other cardiomyopathies, biomarkers may not be as prognostically useful. Further study is warranted in a larger population.