Myocardial Damage Detected by Late Gadolinium Enhancement Cardiac Magnetic Resonance Is Uncommon in Peripartum Cardiomyopathy.

BACKGROUND: In peripartum cardiomyopathy, the prevalence of focal myocardial damage detected by late gadolinium enhancement (LGE) cardiovascular magnetic resonance is important to elucidate mechanisms of myocardial injury and cardiac dysfunction. LGE equates irreversible myocardial injury, but LGE prevalence in peripartum cardiomyopathy is uncertain. METHODS AND RESULTS: Among 100 women enrolled within the Investigations of Pregnancy Associated Cardiomyopathy cohort, we recruited 40 women at 13 centers to undergo LGE cardiovascular magnetic resonance, enrolled within the first 13 weeks postpartum. Follow-up scans occurred at 6 months postpartum, and death/transplant rates at 12 months. Baseline characteristics did not differ significantly in the parent cohort according to cardiovascular magnetic resonance enrollment except for mechanical circulatory support. LGE was noted only in 2 women (5%) at baseline. While left ventricular dysfunction with enlargement was prevalent at baseline cardiovascular magnetic resonance scans (eg, ejection fraction 38% [Q1-Q3 31-50%], end diastolic volume index=108 mL/m2 [Q1-Q3 83-134 mL/m2]), most women demonstrated significant improvements at 6 months, consistent with a low prevalence of LGE. LGE was not related to baseline clinical variables, ejection fraction, New York Heart Association heart failure class, or mortality. Neither of the 2 women who died exhibited LGE. LGE was inversely associated with persistent left ventricular ejection fraction at 6 months (P=0.006). CONCLUSIONS: Factors other than focal myocardial damage detectable by LGE explain the initial transient depressions in baseline left ventricular ejection fraction, yet focal myocardial damage may contribute to persistent myocardial dysfunction and hinder recovery in a small minority. Most women exhibit favorable changes in ventricular function over 6 months. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01085955.

Association of clinical attributes and treadmill walking performance in patients with claudication due to peripheral artery disease.

BACKGROUND: Patients with claudication secondary to peripheral artery disease have a substantial impairment in walking capacity. This study evaluated factors suspected to be correlated with treadmill walking performance in an effort to gain insights into the pathophysiology of the impairment. METHODS: A multivariate model was developed to define the associations between clinical and laboratory biomarkers with treadmill peak walking time (PWT) in patients enrolled in three clinical trials. The model was initially developed in a cohort of 385 patients from one trial using 23 candidate-independent variables and then tested in the combined data from the other two trials (351 patients). RESULTS: The final model was built from 14 variables that met the predefined univariate criteria of P < .15. Main effects remaining in the model were age, resting ankle-brachial index, smoking status, hypertension, statin use, country (United States vs non-United States countries), and high-sensitivity C-reactive protein. The model was highly statistically significant (P < .0001) but explained only a limited portion of the population heterogeneity (r(2) = 0.173). The main effects plus interaction terms had an r(2) = 0.2178. The main effects model was tested in an independent cohort of 351 patients from two other clinical trials in peripheral arterial disease that did not include high-sensitivity C-reactive protein. The model successfully fit the data set, based on prospectively defined root mean squared error and was statistically significant (P = .0005) but had lower overall explanatory power than in the index cohort (r(2) = 0.0687). CONCLUSIONS: As expected, age and ankle-brachial index contributed to exercise limitation among patients with PAD. The association of C-reactive protein, hypertension, and smoking with PWT is consistent with a role for inflammation or oxidative stress in determining treadmill walking performance. In contrast to previous reports from smaller and more homogenous populations, clinical attributes and biomarkers explain only a small portion of PWT heterogeneity.