Variation on chromosome 9p21 is associated with risk of coronary artery disease (CAD). This genomic region contains the CDKN2A and CDKN2B genes which encode the cell cycle regulators p16(INK4a), p14(ARF) and p15(INK4b) and the ANRIL gene which encodes a non-coding RNA. Vascular smooth muscle cell (VSMC) proliferation plays an important role in the pathogenesis of atherosclerosis which causes CAD. We ascertained whether 9p21 genotype had an influence on CDKN2A/CDKN2B/ANRIL expression levels in VSMCs, VSMC proliferation and VSMC content in atherosclerotic plaques. Immunohistochemical examination showed that VSMCs in atherosclerotic lesions expressed p16(INK4a), p14(ARF) and p15(INK4b). Analyses of primary cultures of VSMCs showed that the 9p21 risk genotype was associated with reduced expression of p16(INK4a), p15(INK4b) and ANRIL (P = 1.2 × 10(-5), 1.4 × 10(-2) and 3.1 × 10(-9)) and with increased VSMC proliferation (P = 1.6 × 10(-2)). Immunohistochemical analyses of atherosclerotic plaques revealed an association of the risk genotype with reduced p15(INK4b) levels in VSMCs (P = 3.7 × 10(-2)) and higher VSMC content (P = 5.6 × 10(-4)) in plaques. The results of this study indicate that the 9p21 variation has an impact on CDKN2A and CDKN2B expression in VSMCs and influences VMSC proliferation, which likely represents an important mechanism for the association between this genetic locus and susceptibility to CAD.

Recent genome-wide association studies have revealed an association between variation at the ADAMTS7 locus and susceptibility to coronary artery disease (CAD). Furthermore, in a population-based study cohort, we observed an inverse association between atherosclerosis prevalence and rs3825807, a nonsynonymous SNP (A to G) leading to a Ser-to-Pro substitution in the prodomain of the protease ADAMTS7. In light of these data, we sought a mechanistic explanation for this association. We found that ADAMTS7 accumulated in smooth muscle cells in coronary and carotid atherosclerotic plaques. Vascular smooth muscle cells (VSMCs) of the G/G genotype for rs3825807 had reduced migratory ability, and conditioned media of VSMCs of the G/G genotype contained less of the cleaved form of thrombospondin-5, an ADAMTS7 substrate that had been shown to be produced by VSMCs and inhibit VSMC migration. Furthermore, we found that there was a reduction in the amount of cleaved ADAMTS7 prodomain in media conditioned by VSMCs of the G/G genotype and that the Ser-to-Pro substitution affected ADAMTS7 prodomain cleavage. The results of our study indicate that rs3825807 has an effect on ADAMTS7 maturation, thrombospondin-5 cleavage, and VSMC migration, with the variant associated with protection from atherosclerosis and CAD rendering a reduction in ADAMTS7 function.

Aims Myocardial fibrosis as detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is a powerful prognostic marker in hypertrophic cardiomyopathy (HCM) and may be progressive. The precise mechanisms underlying fibrosis progression are unclear. We sought to assess the extent of LGE progression in HCM and explore potential causal mechanisms and clinical implications. Methods and results Seventy-two HCM patients had two CMR (CMR1-CMR2) at an interval of 5.7 ± 2.8 years with annual clinical follow-up for 6.3 ± 3.6 years from CMR1. A combined endpoint of heart failure progression, cardiac hospitalization, and new onset ventricular tachycardia was assessed. Cine and LGE imaging were performed to assess left ventricular (LV) mass, function, and fibrosis on serial CMR. Stress perfusion imaging and cardiac energetics were undertaken in 38 patients on baseline CMR (CMR1). LGE mass increased from median 4.98 g [interquartile range (IQR) 0.97–13.48 g] to 6.30 g (IQR 1.38–17.51 g) from CMR1 to CMR2. Substantial LGE progression (ΔLGE ≥ 4.75 g) occurred in 26% of patients. LGE increment was significantly higher in those with impaired myocardial perfusion reserve (

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Normal levels of B-type natriuretic peptide (BNP) are not well established in pregnancy. We obtained longitudinal BNP levels in 29 healthy pregnant women in each trimester and postpartum period, and compared these levels to the 25 nonpregnant controls. There were no significant differences among the cases and controls with respect to weight, diastolic blood pressure, and ethnicity. A total of 116 BNP values were obtained during pregnancy. The median (and range) BNP level during pregnancy was 19 (10-143) pg/ml versus 10 (10-37) pg/ml in the nonpregnant controls (p = 0.003). However, there were no statistically significant differences in the median BNP levels at various stages of pregnancy: first trimester 20 (10-115) pg/ml versus the second trimester 18 (10-112) pg/ml (p = 0.8), second trimester 18 pg/ml versus third trimester 26 (10-143) pg/ml (p = 0.06), and third trimester 26 pg/ml versus postpartum18 (10-62) pg/ml (p = 0.08). There were no significant differences between the BNP levels throughout the trimesters and postpartum period. Pregnant BNP levels were approximately twice as high as the nonpregnant BNP levels. Our study is unique in evaluating longitudinal changes in BNP levels in normal pregnancies and the postpartum period in comparison with healthy, nonpregnant controls. It demonstrates that pregnant BNP levels are approximately 2-fold higher than their nonpregnant counterparts, and do not significantly fluctuate during pregnancy. In conclusion, pregnancy is associated with a significant, but small increase in the BNP levels compared with nonpregnant women.

Genome-wide association studies have revealed an association between coronary heart disease (CHD) and genetic variation on chromosome 13q34, with the lead single nucleotide polymorphism rs4773144 residing in the COL4A2 gene in this genomic region. We investigated the functional effects of this genetic variant. Analyses of primary cultures of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) from different individuals showed a difference between rs4773144 genotypes in COL4A2 and COL4A1 expression levels, being lowest in the G/G genotype, intermediate in A/G and highest in A/A. Chromatin immunoprecipitation followed by allelic imbalance assays of primary cultures of SMCs and ECs that were of the A/G genotype revealed that the G allele had lower transcriptional activity than the A allele. Electrophoretic mobility shift assays and luciferase reporter gene assays showed that a short DNA sequence encompassing the rs4773144 site interacted with a nuclear protein, with lower efficiency for the G allele, and that the G allele sequence had lower activity in driving reporter gene expression. Analyses of cultured SMCs from different individuals demonstrated that cells of the G/G genotype had higher apoptosis rates. Immunohistochemical and histological examinations of ex vivo atherosclerotic coronary arteries from different individuals disclosed that atherosclerotic plaques with the G/G genotype had lower collagen IV abundance and thinner fibrous cap, a hallmark of unstable, rupture-prone plaques. A study of a cohort of patients with angiographically documented coronary artery disease showed that patients of the G/G genotype had higher rates of myocardial infarction, a phenotype often caused by plaque rupture. These results indicate that the CHD-related genetic variant at the COL4A2 locus affects COL4A2/COL4A1 expression, SMC survival, and atherosclerotic plaque stability, providing a mechanistic explanation for the association between the genetic variant and CHD risk.

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recommended by the American College of Obstetricians and Gynecologists, the investigators also evaluated the third maneuver used after those maneuvers were unsuccessful. Rubin maneuver was less successful than delivery of the posterior shoulder [odds ratio, 0.33; 95% confidence interval (CI), 0.11-0.98]. Risk of neonatal injury increased from 5.5% to 6% to 10% to 16% to 23.5% as the number of maneuvers used increased from 1 to 5 or more, respectively. Multiple logistic regression of neonatal injury based on exposure to the specific maneuvers found odds ratios of 1.43 (CI, 0.53-3.86), 0.98 (CI, 0.51-1.86), 2.22 (CI, 1.22-4.04), 1.54 (CI, 0.83-2.85), and 1.36 (CI, 0.71-2.61) for the McRoberts, suprapubic pressure, Woods corkscrew, Rubin maneuver, and delivery of posterior shoulder, respectively. Overall, 10 of the 12 centers used the McRoberts maneuver and suprapubic pressure as the primary maneuvers in 100% of their cases; the other 2 centers used these procedures in 94.9% and 98.0% of cases.Delivery of the posterior shoulder was superior to other maneuvers after failure of the McRoberts and suprapubic pressure maneuvers in the acute management of shoulder dystocia with a comparable rate of neonatal injury. The need for and use of additional maneuvers was associated with higher rates of neonatal injury.