Echocardiography and Outcomes in African Americans (page 518)
African Americans with hypertension have a higher proportion of left ventricular (LV) hypertrophy than other ethnic groups and are at increased risk for adverse cardiovascular and renal outcomes. In this issue of Hypertension, Peterson et al report the first study to evaluate the relationship among LV hypertrophy, diastolic dysfunction, and adverse outcomes in blacks with hypertensive chronic kidney disease. Baseline echocardiography was obtained in 691 participants in the African American Study of Hypertension and Kidney Disease (AASK) Cohort. Subjects were followed-up during a 5-year period with blood pressure treatment goal of <130/80 mm Hg. After adjustment for risk factors, exposures, and clinical variables, a strong independent relationship persisted between LV mass and subsequent cardiovascular events but not renal events. Every 10 g/m2.7 increase in baseline LV mass index was associated with a 16% increased risk of a cardiovascular event. Echo Doppler measures, including lower systolic tissue Doppler velocities and diastolic parameters reflecting a less compliant LV (short deceleration time and abnormal mitral inflow E/A ratios), were also associated with significantly increased risk of subsequent hospitalization for heart failure, even after adjustment for risk factors, exposures, clinical variables, and LV mass. This study highlights that readily available echocardiographic parameters of LV mass and diastolic function can identify those patients with hypertensive CKD (chronic kidney disease) at high risk for adverse outcomes. These patients may benefit from aggressive risk factor modification.
Plasma Lipidomic Signature of Hypertension (page 621)
Human plasma exhibits a rich diversity of lipid species. Rapid and accurate technologies are currently available to quantify the plasma lipidome with a clinically meaningful resolution. The diversity of the plasma lipidome is gaining research interest because of its association with several chronic diseases, including metabolic syndrome and its components. Because hypertension is a crucial component of metabolic syndrome, association of 319 lipid species in the plasma was examined with 4 hypertension outcomes: systolic blood pressure, diastolic blood pressure, mean arterial pressure, and incident hypertension in the ongoing San Antonio Family Heart Study (SAFHS) comprising 1192 Mexican Americans from 42 large and extended families. Robust statistical analyses were conducted using SOLAR. The diacylglycerol class of lipids, in general, and 2 diacylglycerol lipid species, in particular (DG 16:0/22:5 and DG 16:0/22:6), showed a consistent, significant, and independent association with all 4 outcomes. Moreover, both of these species showed a significant genetic and environmental correlation with the liability of incident hypertension. These results indicate a specific perturbation in the diacylglycerol metabolism in hypertension. Although replication in other populations is needed before definitive conclusions can be drawn, these observations bring forth the possibility of a novel family of early markers of hypertension based on the plasma lipidome.
Syncytial Aggregates in Preeclampsia (page 608)
Preeclampsia is associated with increased shedding of placental fragments into the maternal circulation. To investigate whether placental tissue is retained in maternal organs, we performed a nationwide study to collect autopsy material of women who died during pregnancy. In this issue of Hypertension, Buurma and Penning et al report that multinucleate aggregates in the maternal lungs originate from the placenta, and that these aggregates retain the antiangiogenic protein sFlt-1 that contributes to the pathogenesis of preeclampsia. The number of these aggregates, and their sFlt-1 content, was found to be significantly higher among the women with preeclampsia.
The presence of these aggregates within maternal lungs may have several implications.
First, as we observed syncytial aggregates as early as the first trimester in the maternal lungs, one may speculate that the release and transfer of syncytial aggregates to the maternal compartment is an early event in the pathogenesis of preeclampsia. The presence of these aggregates in maternal organs may play a key role in the disturbed immune tolerance of the fetus during preeclamptic pregnancies.
Second, these retained sFlt-1 containing aggregates may be a source of sFlt-1 production after delivery, thereby potentially contributing to postpartum complications of preeclampsia. Finally, the release of vital cells from the placenta may result in chimerism, as fetal cells can be retained in the maternal blood and organs for decades after delivery.
- © 2013 American Heart Association, Inc.