Diastolic dysfunction and clinical outcomes after transcatheter or surgical aortic valve replacement in patients with atypical aortic valve stenosis.

BACKGROUND: Diastolic dysfunction is a predictor of poor outcomes in many cardiovascular conditions. At present, it is unclear whether diastolic dysfunction predicts adverse outcomes in patients with atypical aortic stenosis who undergo aortic valve replacement (AVR). METHODS: Five hundred and twenty-three patients who underwent transcatheter AVR (TAVR) (n = 303) and surgical AVR (SAVR) (n = 220) at a single institution were included in our analysis. Baseline left and right heart invasive hemodynamics were assessed. Baseline transthoracic echocardiograms were reviewed to determine aortic stenosis subtype and parameters of diastolic dysfunction. Aortic stenosis subtype was categorized as typical (normal flow, high-gradient) aortic stenosis, classical, low-flow, low-gradient (cLFLG) aortic stenosis, and paradoxical, low-flow, low-gradient (pLFLG) aortic stenosis. Cox proportional hazard models were utilized to examine the relation between invasive hemodynamic or echocardiographic variables of diastolic dysfunction, aortic stenosis subtype, and all-cause mortality. Propensity-score analysis was performed to study the relation between aortic stenosis subtype and the composite outcome [death/cerebrovascular accident (CVA)]. RESULTS: The median STS risk was 5.3 and 2.5% for TAVR and SAVR patients, respectively. Relative to patients with typical aortic stenosis, patients with atypical (cLFLG and pLFLG) aortic stenosis displayed a significantly higher prevalence of diastolic dysfunction (LVEDP ≥ 20mmHg, PCWP ≥ 20mmHg, echo grade II or III diastolic dysfunction, and echo-PCWP ≥ 20mmHg) and, independently of AVR treatment modality, had a significantly increased risk of death. In propensity-score analysis, patients with atypical aortic stenosis had higher rates of death/CVA than typical aortic stenosis patients, independently of diastolic dysfunction and AVR treatment modality. CONCLUSION: We demonstrate the novel observation that compared with patients with typical aortic stenosis, patients with atypical aortic stenosis have a higher burden of diastolic dysfunction. We corroborate the worse outcomes previously reported in atypical versus typical aortic stenosis and demonstrate, for the first time, that this observation is independent of AVR treatment modality. Furthermore, the presence of diastolic dysfunction does not independently predict outcome in atypical aortic stenosis regardless of treatment type, suggesting that other factors are responsible for adverse clinical outcomes in this higher risk cohort.

Bifurcation pulmonary venoplasty and stenting for recalcitrant pulmonary vein stenosis after surgical pulmonary vein reconstruction.

Pulmonary vein stenosis (PVS) is a rare, severe, and potentially fatal complication most often arising from pulmonary vein ablation for medication refractory, symptomatic, and permanent atrial fibrillation. At present, the optimal approach for the management of PVS remains to be defined. Here, we describe a unique case of bifurcation pulmonary venoplasty and stenting in a patient with recalcitrant PVS after surgical reconstruction of her pulmonary veins. To our knowledge, this is the first such report of its kind. .

Crohn's colitis-induced myocarditis.

Myocarditis can be idiopathic or arise in response to numerous systemic insults. Myocarditis occurring in the setting of an exacerbation of inflammatory bowel disease is a rare extra-intestinal manifestation of both ulcerative and Crohn's-related colitis. Here, we present a unique case of a 56-year-old female patient presenting with an acute Crohn's colitis flare that was eventually complicated by myocarditis. Our case is unique in that we clearly delineate the clinical course and development of myocarditis in a patient with focal myocardial inflammation in a pattern that is atypical for myocarditis. .

Interventricular differences in myofilament function in experimental congestive heart failure.

This study was conducted to identify molecular mechanisms which explain interventricular differences in myofilament function in experimental congestive heart failure (CHF). CHF was induced in rats by chronic aortic banding or myocardial infarction for 32-36 weeks. Right and left ventricular (RV, LV) myocytes were mechanically isolated, triton-skinned, and attached to a force transducer and motor arm. Myofilament force-[Ca(2+)] relations assessed maximal Ca(2+)-saturated force (F (max)) and the [Ca(2+)] at 50% of F (max) (EC(50)). Myofilament protein phosphorylation was determined via ProQ diamond phospho-staining. Protein kinase C (PKC)-α expression/activation and site-specific phosphorylation of cardiac troponin I (cTnI) and cardiac troponin T (cTnT) were measured via immunoblotting. Relative to controls, failing RV myocytes displayed a ~45% decrease in F (max) with no change in EC(50), whereas failing LV myocytes displayed a ~45% decrease in F (max) and ~50% increase in EC(50). Failing LV myofilaments were less Ca(2+)-sensitive (37% increase in EC(50)) than failing RV myofilaments. Expression and activation of PKC-α was increased twofold in failing RV myocardium and relative to the RV, PKC-α was twofold higher in the failing LV, while PKC-ß expression was unchanged by CHF. PKC-α-dependent phosphorylation and PP1-mediated dephosphorylation of failing RV myofilaments increased EC(50) and increased F (max), respectively. Phosphorylation of cTnI and cTnT was greater in failing LV myofilaments than in failing RV myofilaments. RV myofilament function is depressed in experimental CHF in association with increased PKC-α signaling and myofilament protein phosphorylation. Furthermore, myofilament dysfunction is greater in the LV compared to the RV due in part to increased PKC-α activation and phosphorylation of cTnI and cTnT.

Diet quality and the risk of cardiovascular disease: the Women's Health Initiative (WHI).

BACKGROUND: The association between diet quality and risk of incident cardiovascular disease (CVD) or heart failure (HF) in postmenopausal women is uncertain. OBJECTIVE: This study aimed to determine whether a conventional index [Alternate Healthy Eating Index (AHEI)] or a novel index [Women's Health Initiative (WHI) Dietary Modification Index (DMI)] of diet quality was associated with the risk of incident CVD or HF in the WHI Observational Study (WHI-OS). DESIGN: The WHI-OS is an observational cohort study of 93,676 women aged 50-79 y of diverse ethnicity and backgrounds followed for an average of 10.0 y for CVD events. The individual components of the AHEI and DMI were determined from the baseline WHI food-frequency questionnaire. Incident CVD was a composite of nonfatal myocardial infarction, coronary heart disease death, stroke, coronary revascularization, and incident HF. The association between AHEI or DMI and incident CVD or incident HF was determined by using Cox models adjusted for traditional CVD and HF risk factors. RESULTS: Women with a DMI in the highest quintile had hazard ratios (HRs) of 0.88 (95% CI: 0.80, 0.95) and 0.91 (95% CI: 0.78, 1.06) for incident CVD and HF, respectively. Women with an AHEI in the highest quintile had HRs of 0.77 (95% CI: 0.70, 0.84) and 0.70 (95% CI: 0.59, 0.82) for incident CVD and HF, respectively. CONCLUSION: Overall, adherence to current nutrient guidelines (as indexed by the DMI) are associated with lower total CVD risk, and additional dietary factors (as indexed by the AHEI) were associated with a lower risk of CVD and HF.

Fish intake and the risk of incident heart failure: the Women's Health Initiative.

BACKGROUND: Whether fish or the fatty acids they contain are independently associated with risk for incident heart failure (HF) among postmenopausal women is unclear. METHODS AND RESULTS: The baseline Women's Health Initiative Observational Study cohort consisted of 93 676 women ages 50 to 79 years of diverse ethnicity and background, of which 84 493 were eligible for analyses. Intakes of baked/broiled fish, fried fish, and omega-3 fatty acid (eicosapentaenoic acid+docosahexaenoic acid, α-linolenic acid), and trans-fatty acid were determined from the Women's Health Initiative food frequency questionnaire. Baked/broiled fish consumption was divided into 5 frequency categories: <1/mo (referent), 1 to 3/mo, 1 to 2/wk, 3 to 4/wk, ≥5/wk. Fried fish intake was grouped into 3 frequency categories: <1/mo (referent), 1-3/mo, and ≥1/wk. Associations between fish or fatty acid intake and incident HF were determined using Cox models adjusting for HF risk factors and dietary factors. Baked/broiled fish consumption (≥5 servings/wk at baseline) was associated with a hazard ratio of 0.70 (95% confidence interval, 0.51 to 0.95) for incident HF. In contrast, fried fish consumption (≥1 serving/wk at baseline) was associated with a hazard ratio of 1.48 (95% confidence interval, 1.19 to 1.84) for incident HF. No significant associations were found between eicosapentaenoic acid+docosahexaenoic acid, α-linolenic acid, or trans-fatty acid intake and incident HF. CONCLUSIONS: Increased baked/broiled fish intake may lower HF risk, whereas increased fried fish intake may increase HF risk in postmenopausal women.

Magnesium physiology and pathogenic mechanisms that contribute to the development of the metabolic syndrome.

The clinical and public health impact of the metabolic syndrome (MetS) has increased substantially in recent years. MetS is defined by a constellation of cardiovascular disease risk factors including: insulin resistance, elevated blood pressure, impaired glucose tolerance, central obesity, and atherogenic dyslipidemia as well as impaired clotting, increased inflammatory burden, and oxidative stress. Recently, there has been burgeoning experimental, clinical, and epidemiological data that provides strong evidence that dietary magnesium intake and supplementation are inversely associated with the risk for MetS and its components. In this review, we describe and discuss the myriad of integrated physiological mechanisms through which magnesium deficiency and the resultant altered magnesium status may lead to the development of the MetS and each of its components.

Augmented protein kinase C-alpha-induced myofilament protein phosphorylation contributes to myofilament dysfunction in experimental congestive heart failure.

It is becoming clear that upregulated protein kinase C (PKC) signaling plays a role in reduced ventricular myofilament contractility observed in congestive heart failure. However, data are scant regarding which PKC isozymes are involved. There is evidence that PKC-alpha may be of particular importance. Here, we examined PKC-alpha quantity, activity, and signaling to myofilaments in chronically remodeled myocytes obtained from rats in either early heart failure or end-stage congestive heart failure. Immunoblotting revealed that PKC-alpha expression and activation was unaltered in early heart failure but increased in end-stage congestive heart failure. Left ventricular myocytes were isolated by mechanical homogenization, Triton-skinned, and attached to micropipettes that projected from a force transducer and motor. Myofilament function was characterized by an active force-[Ca(2+)] relation to obtain Ca(2+)-saturated maximal force (F(max)) and myofilament Ca(2+) sensitivity (indexed by EC(50)) before and after incubation with PKC-alpha, protein phosphatase type 1 (PP1), or PP2a. PKC-alpha treatment induced a 30% decline in F(max) and 55% increase in the EC(50) in control cells but had no impact on myofilament function in failing cells. PP1-mediated dephosphorylation increased F(max) (15%) and decreased EC(50) ( approximately 20%) in failing myofilaments but had no effect in control cells. PP2a-dependent dephosphorylation had no effect on myofilament function in either group. Lastly, PP1 dephosphorylation restored myofilament function in control cells hyperphosphorylated with PKC-alpha. Collectively, our results suggest that in end-stage congestive heart failure, the myofilament proteins exist in a hyperphosphorylated state attributable, in part, to increased activity and signaling of PKC-alpha.

Cardiac dysfunction and heart failure are associated with abnormalities in the subcellular distribution and amounts of oligomeric muscle LIM protein.

Prolonged hemodynamic overload results in cardiac hypertrophy and failure with detrimental changes in myocardial gene expression and morphology. Cysteine-rich protein 3 or muscle LIM protein (MLP) is thought to be a mechanosensor in cardiac myocytes. Therefore, the subcellular location of MLP may have functional implications in health and disease. Our hypothesis is that MLP becomes mislocalized after prolonged overload, resulting in impaired mechanosensing in cardiac myocytes. Using the techniques of biochemical subcellular fractionation and immunocytochemistry, we found MLP exhibits oligomerization in the membrane and cytoskeleton of cultured cardiac rat neonatal myocytes. Nuclear MLP was always monomeric. MLP translocated to the nucleolus in response to 10% cyclic stretch at 1 Hz for 48 h. This was associated with a threefold increase in S6 ribosomal protein (P < 0.01; n = 3 cultures). Adenoviral overexpression of MLP also resulted in a twofold increase in S6 protein, suggesting that MLP can activate ribosomal protein synthesis in the nucleolus. In ventricles from aortic-banded and myocardially infarcted rat hearts, nuclear MLP increased by twofold (P < 0.01; n = 7) along with a significant decrease in the nonnuclear oligomeric fraction. The ratio of nuclear to nonnuclear MLP increased threefold in both groups (P < 0.01; n = 7). In failing human hearts, there was almost a complete loss of oligomeric MLP. Using a flag-tagged adenoviral MLP, we demonstrate that the COOH terminus is required for oligomerization and that this is a precursor to stretch sensing and subsequent nuclear translocation. Therefore, reduced oligomeric MLP in the costamere and cytoskeleton may contribute to impaired mechanosensing in heart failure.

Left ventricular myofilament dysfunction in rat experimental hypertrophy and congestive heart failure.

It is currently unclear whether left ventricular (LV) myofilament function is depressed in experimental LV hypertrophy (LVH) or congestive heart failure (CHF). To address this issue, we studied pressure overload-induced LV hypertrophy (POLVH) and myocardial infarction-elicited congestive heart failure (MICHF) in rats. LV myocytes were isolated from control, POLVH, and MICHF hearts by mechanical homogenization, skinned with Triton, and attached to micropipettes that projected from a sensitive force transducer and high-speed motor. A subset of cells was treated with either unphosphorylated, recombinant cardiac troponin (cTn) or cTn purified from either control or failing ventricles. LV myofilament function was characterized by the force-[Ca(2+)] relation yielding Ca(2+)-saturated maximal force (F(max)), myofilament Ca(2+) sensitivity (EC(50)), and cooperativity (Hill coefficient, n(H)) parameters. POLVH was associated with a 35% reduction in F(max) and 36% increase in EC(50). Similarly, MICHF resulted in a 42% reduction in F(max) and a 30% increase in EC(50). Incorporation of recombinant cTn or purified control cTn into failing cells restored myofilament Ca(2+) sensitivity toward levels observed in control cells. In contrast, integration of cTn purified from failing ventricles into control myocytes increased EC(50) to levels observed in failing myocytes. The F(max) parameter was not markedly affected by troponin exchange. cTnI phosphorylation was increased in both POLVH and MICHF left ventricles. We conclude that depressed myofilament Ca(2+) sensitivity in experimental LVH and CHF is due, in part, to a decreased functional role of cTn that likely involves augmented phosphorylation of cTnI.

Magnesium intake and the metabolic syndrome: epidemiologic evidence to date.

The importance of magnesium intake in relation to the metabolic syndrome has been increasingly recognized. Magnesium is an essential mineral, critical for a number of metabolic functions in the human body. The major dietary sources of magnesium intake include whole grains, legumes, nuts, and green leafy vegetables. Animal studies indicate a pivotal role of magnesium in glucose homeostasis and insulin secretion and action. Experimental and clinical studies suggest that magnesium intake may be inversely related to the risk of hypertension and type 2 diabetes mellitus, and may decrease blood triglyceride and increase high-density lipoprotein cholesterol levels. The purpose of this brief review is to summarize the epidemiologic data relating magnesium to the metabolic syndrome and to discuss the potential mechanisms.