Direct Oral Anticoagulants After Percutaneous Patent Foramen Ovale (PFO) Closure: A Call for Caution.

BACKGROUND Transient atrial fibrillation (AF) following percutaneous patent foramen ovale (PFO) closure is common. Anticoagulation therapy should be considered in selected cases of prolonged AF after PFO closure, but guidelines do not provide clear recommendations on indication or choice of anticoagulant therapy for patients with post-procedural AF. CASE REPORT A 45-year-old woman presented with cryptogenic stroke verified by magnetic resonance imaging (MRI). Echocardiography revealed a PFO, which was closed percutaneously using a Gore septal occluder (25 mm). She was discharged on aspirin monotherapy (75 mg oral daily) according to institutional standard. Three weeks later, she presented with atrial fibrillation (AF). A direct oral anticoagulant (DOAC) (rivaroxaban 20 mg once daily) was initiated and aspirin was discontinued. After 4 months of follow-up, a routine echocardiography revealed large thrombi attached to both sides of the PFO occluder. CONCLUSIONS DOACs may be ineffective in preventing thrombus formation on device surfaces. Until more evidence has been provided, we suggest that DOACs are not routinely used for stroke prevention in patients following PFO closure or similar procedures within the first 3 months after device implantation.

Renal denervation in treatment-resistant essential hypertension. A randomized, SHAM-controlled, double-blinded 24-h blood pressure-based trial.

BACKGROUND: Renal denervation (RDN), treating resistant hypertension, has, in open trial design, been shown to lower blood pressure (BP) dramatically, but this was primarily with respect to office BP. METHOD: We conducted a SHAM-controlled, double-blind, randomized, single-center trial to establish efficacy data based on 24-h ambulatory BP measurements (ABPM). Inclusion criteria were daytime systolic ABPM at least 145 mmHg following 1 month of stable medication and 2 weeks of compliance registration. All RDN procedures were carried out by an experienced operator using the unipolar Medtronic Flex catheter (Medtronic, Santa Rosa, California, USA). RESULTS: We randomized 69 patients with treatment-resistant hypertension to RDN (n = 36) or SHAM (n = 33). Groups were well balanced at baseline. Mean baseline daytime systolic ABPM was 159 ±â€Š12 mmHg (RDN) and 159 ±â€Š14 mmHg (SHAM). Groups had similar reductions in daytime systolic ABPM compared with baseline at 3 months [-6.2 ±â€Š18.8 mmHg (RDN) vs. -6.0 ±â€Š13.5 mmHg (SHAM)] and at 6 months [-6.1 ±â€Š18.9 mmHg (RDN) vs. -4.3 ±â€Š15.1 mmHg (SHAM)]. Mean usage of antihypertensive medication (daily defined doses) at 3 months was equal [6.8 ±â€Š2.7 (RDN) vs. 7.0 ±â€Š2.5 (SHAM)].RDN performed at a single center and by a high-volume operator reduced ABPM to the same level as SHAM treatment and thus confirms the result of the HTN3 trial. CONCLUSION: Further, clinical use of RDN for treatment of resistant hypertension should await positive results from double-blinded, SHAM-controlled trials with multipolar ablation catheters or novel denervation techniques.

Cardiovascular effects of cholecalciferol treatment in dialysis patients--a randomized controlled trial.

BACKGROUND: Patients on chronic dialysis are at increased risk of vitamin D deficiency. In observational studies plasma 25-hydroxyvitamin D (p-25(OH) D) levels are inversely correlated with plasma BNP and adverse cardiovascular outcomes. Whether a causal relation exists has yet to be established. The aim of this study was to test the hypothesis that cholecalciferol supplementation improves cardiac function and reduces blood pressure (BP) and pulse wave velocity (PWV) in patients on chronic dialysis. METHODS: In a randomized, placebo-controlled, double-blind study, we investigated the effect of 75 µg (3000 IU) cholecalciferol daily for 6 months, in patients on chronic dialysis. We performed two-dimensional echocardiography, with doppler and tissue-doppler imaging, 24-h ambulatory BP (24-h BP), PWV, augmentation index (AIx), central BP (cBP) and brain natriuretic peptide (BNP) measurements at baseline and after 6 months. RESULTS: Sixty-four patients were allocated to the study. Fifty dialysis patients with a mean age of 68 years (range: 46-88) and baseline p-25(OH) D of 28 (20;53) nmol/l completed the trial. Cholecalciferol increased left ventricular (LV) volume, but had no impact on other parameters regarding LV structure or left atrial structure. LV systolic function, LV diastolic function, PWV, cBP, AIx and BNP were not changed in placebo or cholecalciferol group at follow-up. 24-h BP decreased significantly in placebo group and tended to decrease in cholecalciferol group without any difference between treatments. CONCLUSION: Six months of cholecalciferol treatment in patients on chronic dialysis did not improve 24-h BP, arterial stiffness or cardiac function. TRIAL REGISTRATION: NCT01312714, Registration Date: March 9, 2011.

Effect of potassium supplementation on renal tubular function, ambulatory blood pressure and pulse wave velocity in healthy humans.

BACKGROUND: Potassium is the main intracellular cation, which contributes to keeping the intracellular membrane potential slightly negative and elicits contraction of smooth, skeletal and cardiac muscle. A change in potassium intake modifies both cardiovascular and renal tubular function. The purpose of the trial was to investigate the effect of dietary potassium supplementation, 100 mmol daily in a randomized, placebo-controlled, crossover trial of healthy participants during two periods of 28 days duration. The participants (N = 21) received a diet that was standardized regarding energy requirement, and sodium and water intake. METHODS: 24-hour ambulatory blood pressure (ABP) and applanation tonometry were used to assess blood pressure, pulse wave velocity (PWV), augmentation index (AIx) and central blood pressure (CBP). Immunoassays were used for measurements of plasma concentrations of vasoactive hormones: renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), atrial natriuretic peptide (ANP), vasopressin (AVP), pro-brain natriuretic peptide (pro-BNP),endothelin (Endo), urinary excretions of aquaporin 2 (AQP2), cyclic AMP (cAMP), and the ß-fraction of the epithelial sodium channel (ENaC(ß)). RESULTS: AQP2 excretion increased during potassium supplementation, and free water clearance fell. The changes in urinary potassium excretion and urinary AQP2 excretion were significantly and positively correlated. Aldo increased. GFR, u-ENaC- ß, PRC, Ang II, ANP, BNP, Endo, blood pressure and AI were not significantly changed by potassium supplementation, whereas PWV increased slightly. CONCLUSIONS: Potassium supplementation changed renal tubular function and increased water absorption in the distal part of the nephron. In spite of an increase in aldosterone in plasma, blood pressure remained unchanged after potassium supplementation.