Rohan Samson

Vascular and Microvascular Endothelial Function in Heart Failure With Preserved Ejection Fraction

BACKGROUND Assessment of vascular endothelial function lacks consistency, and microvascular endothelial function has been only partly assessed in heart failure with preserved ejection fraction (HFpEF). METHODS The study population consisted of 90 patients: 45 had well documented HFpEF, and 45 had hypertension and no history or evidence of heart failure. Patients with hypertension but no heart failure were matched with HFpEF patients for age, sex, and diabetes. They served as control subjects. All patients underwent 2-dimensional Doppler echocardiography and vascular function measurements, including assessment of arterial wave reflections and arterial stiffness, brachial artery flow-mediated dilation (FMD), and forearm cutaneous blood flow with the use of a laser Doppler flow probe at rest and after release of arterial occlusion for 5 minutes. RESULTS Brachial artery FMD was lower in HFpEF than in control subjects (median (IQR) 3.6 (0.4-7.4) vs. 7.2 (3.2-17.2)%, P = .001). Forearm cutaneous blood flow at rest was similar in HFpEF and control subjects (P = .68). After release of arterial occlusion, forearm cutaneous peak blood flow was lower in HFpEF than in control subjects (P = .03). Estimated aortic systolic and mean blood pressures were similar in HFpEF and control subjects, whereas pulse pressure and pressure augmentation were greater in HFPEF than in control subjects (both P < .05). CONCLUSION Compared with hypertensive control subjects, patients with HFpEF had a depressed endothelial function in the forearm vasculature and microvasculature.

Clinical Phenotypes in Heart Failure With Preserved Ejection Fraction

Over the past 2 decades, the syndrome of heart failure with preserved ejection fraction (HFpEF) received a lot of attention.[1][1]–[19][2] However, little therapeutic progress was made.[20][3]–[27][4] Among the issues that may account for the modest therapeutic progress, one appears to be

Editor’s Choice-Recent therapeutic trials on fluid removal and vasodilation in acute heart failure

Recent therapeutic trials regarding the management of acute heart failure (AHF) failed to demonstrate the efficacy of newer therapeutic modalities and agents. Low- versus high-dose and continuous administration of furosemide were shown not to matter. Ultrafiltration was not found to be more efficacious than sophisticated diuretic therapy including dose-adjusted intravenous furosemide and metolazone. Dopamine and nesiritide were not shown to be superior to current therapy. Tezosentan and tovalptan had no effect on mortality. The development of rolofylline was terminated due to adverse effect (seizures). Lastly, preliminary experience with serelaxin indicates a mortality improvement at six months that remains to be confirmed. The disappointing findings of these recent trials may reflect the lack of efficacy of newer therapeutic modalities and agents. Alternatively the disappointing findings of these recent trials may be in part due to methodological issues. The AHF syndrome is complex with many clinical phenotypes. Failure to match clinical phenotypes and therapeutic modalities is likely to be partly responsible for the disappointing findings of recent AHF trials.

Obesity-Associated Hypertension: the Upcoming Phenotype in African-American Women

Purpose of ReviewThe present obesity epidemic particularly affects African-American women. Whether the obesity epidemic will alter the hypertension phenotype in African-American women is entertained.Recent FindingsThe prevalence of morbid obesity is steadily increasing in African-American women, who are prone to developing hypertension (HTN) even in the absence of obesity. The obesity-associated hypertension phenotype is characterized by marked sympathetic nervous system activation and resistance/refractoriness to antihypertensive therapy. Weight loss achieved through lifestyle interventions and pharmacotherapy has a modest and rarely sustained antihypertensive effect. In contrast, bariatric surgery has a sustained antihypertensive effect, as evidenced by normalization of hypertension or lessening of antihypertensive therapy.SummaryThe prevalence of HTN and its obesity-associated phenotype is likely to increase in African-American women over the next decades. Obese African-American women may be increasingly referred for bariatric surgery when hypertension remains uncontrolled despite lifestyle interventions and pharmacological therapy for weight loss and blood pressure (BP) control.

Cardiac Adrenergic Nervous System and Left Ventricular Remodeling.

Abstract:Heightened cardiac adrenergic nervous system (ANS) activity and progression of left ventricular (LV) remodeling are temporally related in patients with systolic heart failure. Whether cardiac ANS activation directly contributes to or merely accompanies LV remodeling remains an unresolved issue. Human and experimental data that directly link cardiac ANS activation to LV remodeling and worsening heart failure are first reviewed, including cardiac norepinephrine spillover. Alterations of beta adrenergic receptor signaling pathways are then addressed with emphasis on the mechanisms that may mediate the beneficial effect of beta adrenergic receptor blockade on LV remodeling. Lastly, alternative approaches to beta adrenergic receptor blockade for lessening cardiac ANS activation and reversing cardiac ANS-induced LV remodeling are discussed. A large body of work now links LV remodeling to cardiac ANS activation. However, the precise mechanisms that link cardiac ANS activation to LV remodeling are still to be fully understood. Fully understanding of these mechanisms may uncover new therapeutic approaches.

Pathophysiology and Potential Non-Pharmacologic Treatments of Obesity or Kidney Disease Associated Refractory Hypertension

Purpose of ReviewThe review assesses the role of non-pharmacologic therapy for obesity and chronic kidney disease (CKD) associated refractory hypertension (rf HTN).Recent FindingsHypertensive patients with markedly heightened sympathetic nervous system (SNS) activity are prone to develop refractory hypertension (rfHTN). Patients with obesity and chronic kidney disease (CKD)-associated HTN have particularly heightened SNS activity and are at high risk of rfHTN. The role of bariatric surgery is increasingly recognized in treatment of obesity.SummaryCurrent evidence advocates for a greater role of bariatric surgery in the management of obesity-associated HTN. In contrast, renal denervation does not appear have a role in the management of obesity or CKD-associated HTN. The role of baroreflex activation as adjunctive anti-hypertensive therapy remains to be defined.

Regression of Left Ventricular Mass After Bariatric Surgery

Notwithstanding the presence of hypertension, obstructive sleep apnea, or both, obesity is associated with increased left ventricular (LV) mass. The effects of bariatric surgery on LV mass have been sparsely investigated by M-mode and two-dimensional (2D) echocardiography. Overall, Roux-en-Y gastric bypass, adjustable gastric banding, and sleeve gastrectomy reduce LV mass. However, the reduction in LV mass is extremely variable. Besides duration and severity of obesity, presence of hypertension, obstructive sleep apnea or both, and type of surgical procedures, the inaccuracy of M-mode and 2D echocardiography for assessment of LV mass contributes to the variable effects of bariatric surgery on LV mass. Three-dimensional (3D) echocardiography may obviate the limitations of M-mode 2D echocardiography for assessment of LV mass and allow an accurate appraisal of the effects of bariatric surgery on LV mass.

Device Thrombosis During Destination Therapy.

Background: Device thrombosis remains a complication of long‐term mechanical circulatory support with HeartMate II. Materials and Methods: Retrospective analysis of patients who underwent destination therapy (DT) with HeartMate II from January 2010‐December 2013 at Tulane University Medical Center. Results: Eighteen HeartMate II were implanted for DT. Survival rates were 72.2% at 1 year and 37% at 2 years. Device thrombosis in 7 of the 18 patients (39%) accounted for the low survival rate at 2 years. Known risk factors for device thrombosis were equally present in patients with and without device thrombosis. In contrast to patients without device thrombosis, all patients with device thrombosis had a pre‐existing systemic inflammatory condition. Conclusions: Patients with pre‐existing systemic inflammatory conditions are at risk of device thrombosis during DT.

Sustained Cardiac Recovery Hinges on Timing and Natural History of Underlying Condition

Abstract: The review underlines that advanced heart failure (AHF) patients who experience sustained cardiac recovery in the current left ventricular assist device (LVAD) era have similar clinical characteristics to those who experienced myocardial recovery in the pre‐LVAD era. They are young, do not have coronary artery disease and were treated for idiopathic dilated cardiomyopathy within weeks to months of experiencing symptoms. As recently shown with progressive remodeling of the transverse tubular system, AHF results in myocyte and extracellular matrix alterations that with time become irreversible. Young age, short duration of symptoms and LV systolic dysfunction as evidenced by smaller LV cavity dimension are primary determinants of sustained cardiac recovery in patients with AHF. Mechanical circulatory support can be life saving in patients with low‐cardiac output and end‐organ dysfunction. However, the underlying condition and not mechanical circulatory support appears to be the primary determinant of sustained myocardial recovery.

Visceral Adipose Tissue Accumulation and Residual Cardiovascular Risk

Purpose of the ReviewLow-grade systemic inflammation increases residual cardiovascular risk. The pathogenesis of low-grade systemic inflammation is not well understood.Recent FindingsVisceral adipose tissue accumulates when the subcutaneous adipose tissue can no longer store excess nutrients. Visceral adipose tissue inflammation initially facilitates storage of nutrients but with time become maladaptive and responsible for low-grade systemic inflammation. Control of low-grade systemic inflammation requires reversal of visceral adipose tissue accumulation with intense and sustained aerobic exercise or bariatric surgery. Alternatively, pharmacologic inhibition of the inflammatory signaling pathway may be considered.SummaryReversal visceral adipose tissue accumulation lowers residual cardiovascular risk.