Kazuhiko Kido

Capecitabine-induced ventricular fibrillation arrest: Possible Kounis syndrome

We report the case of capecitabine-induced ventricular fibrillation arrest, possibly secondary to type I Kounis syndrome. A 47-year-old man with a history of T3N1 moderately differentiated adenocarcinoma of the colon, status-post sigmoid resection, was started on adjuvant capecitabine approximately five months prior to presentation of cardiac arrest secondary to ventricular fibrillation. An electrocardiogram (EKG) revealed ST segment elevation on the lateral leads and the patient was taken emergently to the cardiac catheterization laboratory. The catheterization revealed no angiographically significant stenosis and coronary artery disease was ruled out. After ruling out other causes of cardiac arrest, the working diagnosis was capecitabine-induced ventricular fibrillation arrest. As such, an inflammatory work up was sent to evaluate for the possibility of a capecitabine hypersensitivity, or Kounis syndrome, and is the first documented report in the literature to do so when evaluating Kounis syndrome. Immunoglobulin E (IgE), tryptase, and C-reactive protein were normal but histamine, interleukin (IL)-6, and IL-10 were elevated. Histamine elevation supports the suspicion that our patient had type I Kounis syndrome. Naranjo adverse drug reaction probability scale indicates a probable adverse effect due to capecitabine with seven points. A case of capecitabine-induced ventricular fibrillation arrest is reported, with a potential for type 1 Kounis syndrome as an underlying pathology supported by immunologic work up.

Drug-Induced Takotsubo Cardiomyopathy

Background: The most plausible hypothesis for takotsubo cardiomyopathy (TCM) is a catecholamine surge. Direct administration of catecholamines or medications causing catecholamine surge is frequently used in clinical practice. Methods: A Medline/PubMed database search was conducted for case reports or series of drug-induced TCM. All reported cases of drug-induced TCM were systemically identified and analyzed. Results: We identified 157 cases of drug-induced TCM. Fifty-seven (36.3%) cases were related to the administration of exogenous catecholamines. In 50 (31.9%) other cases, there was potential adrenergic effect. This included drugs with adrenergic vasoconstriction properties (3.2%), hyperadrenergic state due to alcohol or opioid withdrawal (7.7%), inhibitors of catecholamine reuptake (14.7%), anaphylactic reaction that is accompanied by catecholamine release (3.2%), and psychological or somatic stress coinciding with the administration of a drug that was thought to be the culprit (3.2%). Overall, 68.2% of these drug-induced TCM cases were catecholamine related. In 14 (8.9%) cases, the likely etiology of cardiomyopathy was chemotherapy-induced coronary vasospasm. Conclusion: Our systematic review showed that over two-thirds of drug-induced TCM cases were due to direct or indirect catecholamine stimulation. The lowest effective dose and shortest duration of catecholamines should be utilized, and alternative therapies should be considered if feasible.

Management of Oral Anticoagulation Therapy After Gastrointestinal Bleeding: Whether to, When to, and How to Restart an Anticoagulation Therapy:

Objective: To evaluate current clinical evidence for management of oral anticoagulation therapy after gastrointestinal bleeding (GIB) with an emphasis on whether to, when to, and how to resume an anticoagulation therapy. Data Sources: Relevant articles from MEDLINE, Cochrane Library, and EMBASE databases were identified from 1946 through May 20, 2017, using the keywords: gastrointestinal hemorrhage or gastrointestinal bleeding and antithrombotic therapy or anticoagulation therapy or warfarin or dabigatran or rivaroxaban or apixaban or edoxaban. Study Selection and Data Extraction: All English-language studies assessing management of oral anticoagulation therapy after GIB were evaluated. Data Synthesis: A total of 9 studies were identified. Four retrospective cohort studies showed that resuming anticoagulation therapy was associated with significantly lower rate of thromboembolism (TE) in the general population. Meta-analyses and prospective cohort studies also supported this finding. Two retrospective cohort studies indicated an increase in GIB when anticoagulation reinitiation occurred in less than 7 days without a decrease in TE. Resuming therapy between 7 and 15 days did not demonstrate a significant increase in GIB or TE. A large retrospective study showed that apixaban was associated with the significantly lowest risk of GIB compared with both rivaroxaban and dabigatran. Conclusion: Anticoagulation therapy resumption is recommended, with resumption being considered between 7 and 14 days following GIB regardless of the therapy chosen. Data for warfarin management after GIB should be applied with caution to direct oral anticoagulants (DOACs) because of the quicker onset and experimental nature of reversal agents. Apixaban may be a preferred option when restarting a DOAC therapy.

Optimal Intensity of Warfarin Therapy in Patients With Mechanical Aortic Valves

Objective: To review the current guidelines and published literature in order to identify the evidence-based international normalized ratio (INR) goal in patients with a mechanical aortic valve. Data Sources: Medline/PubMed, Cochrane and Google Scholar database searches for relevant articles from 1946 through March 2017 were executed using the key words “mechanical aortic valve” and “antithrombotic therapy or anticoagulation therapy or warfarin.” Study Selection and Data Extraction: All English-language observational and interventional studies assessing INR goals in patients with a mechanical aortic valve were evaluated. Results: After low thrombogenic valves became standard in the practice, the INR goal decreased to 2 to 3 in low-risk recipients with most of bileaflet mechanical aortic valves. There is a paucity of data to justify the INR goal of 2 to 3 in high-risk patients. Until further higher evidence is available, it is reasonable to target an INR range of 2.5 to 3.5 in patients with risk factors for thromboembolism with low thrombogenic valves, except for On-X valve. The INR goal in high-risk On-X aortic valve recipients can be managed at 1.5 to 2.5 with low-dose aspirin 3 months after valve implantation. Conclusion: The INR goals of 2 to 3 for low risk and 2.5 to 3.5 for high risk should be considered for bileaflet mechanical aortic valve recipients. Additionally, a lower INR goal of 2 to 3 for the first 3 months after valve replacement followed by an INR goal of 1.5 to 2.5 in both low- and high-risk aortic On-X valve recipients may be considered.

Successful use of rivaroxaban in inferior vena cava thrombosis provoked by multiple traumatic injuries and surgeries: A case report

There is a lack of consensus regarding optimal anticoagulation regimen and duration for inferior vena cava (IVC) thrombus due to the paucity of clinical evidence. A case of IVC thrombus treated with 3 months of rivaroxaban therapy is reported.

Selexipag for the treatment of pulmonary arterial hypertension

PURPOSE The pharmacology, pharmacokinetics, clinical efficacy, safety and tolerability, dosing and administration, and place in therapy of selexipag, an orally administered selective prostacyclin receptor agonist for the treatment of pulmonary arterial hypertension (PAH), are reviewed. SUMMARY The first-in-class oral prostacyclin IP receptor agonist selexipag (Uptravi, Actelion Pharmaceuticals) was approved by the Food and Drug Administration in December 2015. Selexipag is rapidly hydrolyzed to a long-acting metabolite that binds with high selectivity to IP receptors, resulting in vasodilation, inhibition of platelet aggregation, and antiinflammatory effects. Results of a long-term, placebo-controlled, clinical outcomes-driven trial showed that selexipag significantly reduced the occurrence of the composite primary outcome (all-cause mortality and development of PAH-related complications). Selexipag is indicated for use in patients with World Health Organization functional class (FC) II or III disease. The recommended initial selexipag dosage is 200 μg twice daily. Like prostanoid analogs, selexipag has a dose-dependent adverse-effect profile that includes nausea, vomiting, diarrhea, headache, and musculoskeletal pain. Although selexipag offers distinct pharmacologic advantages over other agents for the treatment of PAH, important issues of cost and access must be considered. CONCLUSION Selexipag is an oral prostacyclin IP receptor agonist approved for use as monotherapy or in combination with other therapies to slow PAH progression and reduce the risk of hospitalization in patients with FC II or III symptoms. Its stability and relatively long half-life offer conveniences over conventional prostanoid therapies.

Severe Hypertriglyceridemia Induced by Sirolimus Treated With Medical Management Without Plasmapheresis: A Case Report

Summary: Hypertriglyceridemia and hyperlipidemia are the most remarkable metabolic complications seen with long-term sirolimus therapy. We report the case of a 36-year-old woman status post bilateral lung transplantation on a maintenance immunosuppression regimen of sirolimus, tacrolimus, and prednisone who presented with status migrainosus, chest pain, abdominal discomfort, and triglyceride levels greater than 4425 mg/dL. In previously reported cases of severe hypertriglyceridemia that developed on maintenance sirolimus therapy, plasmapheresis has been utilized as an early strategy to rapidly lower triglycerides in order to minimize the risk of acute complications such as pancreatitis, but our case was managed medically without plasmapheresis. The most recent triglyceride was down to 520 mg/dL 2 months after discontinuation of sirolimus. We estimate the probability of this reaction to sirolimus as probable based on a score of 5 points on the Naranjo scale. This is the first case report to our knowledge that highlights the sole use of oral lipid-lowering drug agents to treat severe hypertriglyceridemia secondary to sirolimus without the use of plasmapheresis. Conclusion: Sirolimus-induced severe hypertriglyceridemia can be managed with oral lipid-lowering agents without plasmapheresis. Clinician needs to be aware of the importance of baseline and regular triglyceride monitoring in patients on sirolimus.

Anticoagulation Therapy in Specific Cardiomyopathies: Isolated Left Ventricular Noncompaction and Peripartum Cardiomyopathy

In 2 distinct entities, left ventricular noncompaction (LVNC) and peripartum cardiomyopathy (PPCM), routine anticoagulation therapy is often used in current practices. However, our systematic review showed that LVNC itself was not associated with the increase in thromboembolism event rates and therapeutic anticoagulation therapy should not be considered only for LVNC, unless there is risk factor for thromboembolism. Current literature justifies prophylactic therapeutic anticoagulation in LVNC with low left ventricular ejection fraction (EF < 40%) and/or atrial fibrillation. Although not specifically studied, the presence of intracardiac thrombi by echocardiography or other imaging studies should also prompt anticoagulation therapy. There is limited evidence available for the use of anticoagulation in patients with PPCM, but our systematic review showed that anticoagulation should be recommended only for patients with PPCM especially with an EF < 35% until EF is recovered, as well as for patients with PPCM treated with bromocriptine.

Comparing the Efficacy and Safety of Direct Oral Anticoagulants With Warfarin in the Morbidly Obese Population With Atrial Fibrillation

Background: The International Society of Thrombosis and Haemostasis recommends avoiding direct oral anticoagulants (DOACs) in morbidly obese patients with a body mass index (BMI) >40 kg/m2 or weight >120 kg because of limited clinical data in this group of patients. Objectives: The objective of this study was to evaluate the efficacy and safety of DOACs in morbidly obese patients with atrial fibrillation or flutter. Methods: A retrospective, single-center cohort study was conducted of patients older than 18 years, with BMI >40 kg/m2 or weight >120 kg, who were diagnosed as having atrial fibrillation or flutter and who received warfarin or DOACs (ie, dabigatran, rivaroxaban, or apixaban). The primary efficacy outcome was the incidence of ischemic stroke or transient ischemic attack (TIA), whereas the primary safety outcome was the incidence of major bleeding. Results: A total of 64 patients in each group were included in the study analysis. The incidence rate of ischemic stroke or TIA was 1.75%/year in the DOAC group compared with 2.07%/year in the warfarin group (rate ratio = 0.84; 95% CI = 0.23 to 3.14; P = 0.80). The incidence rate of major bleeding was 2.18%/year in the DOAC group, compared with 4.97%/year in the warfarin group (rate ratio = 0.44; 95% CI = 0.15 to 1.25; P = 0.11). Conclusion and Relevance: Apixaban and rivaroxaban may be considered as alternatives to warfarin for atrial fibrillation or flutter in morbidly obese patients. Dabigatran use in morbidly obese patients needs caution until further studies are conducted.

Chronologic Changes and Correlates of Loop Diuretic Dose in Patients with Left Ventricular Assist Device

No study has systematically evaluated the prevalence and dosages of diuretic use for patients after left ventricular assist device (LVAD) implantation. The primary objective was to characterize chronologic change in prevalence and doses of loop diuretics after LVAD placement. The secondary objective was to identify correlates of actual doses of loop diuretics. We retrospectively reviewed medical records of adult patients with LVAD implantation at the University of Kentucky. Prevalence of diuretic use and furosemide equivalent dose were assessed before LVAD implantation and at seven time points thereafter: 1 week, 1 month, 3 months, 6 months, 1 year, 18 months, and 2 years. Correlation analyses and linear mixed modeling were used to identify correlates of diuretic dose before and after LVAD implantation. Eighty-two consecutive eligible patients were reviewed. The prevalence of loop diuretic use was 95% at baseline but significantly lower than that at all subsequent time points (p < 0.048 for all). Nevertheless, more than half of patients on whom we had such follow-up data were on loop diuretics 2 years after LVAD implantation. Average furosemide equivalent dose was significantly lower at every time point after implantation compared with baseline (p < 0.006 for all). Blood urine nitrogen (BUN) was the most robust predictor of dose after LVAD implant. The prevalence and average furosemide equivalent dose were significantly reduced after LVAD implantation, but the use of loop diuretic remained more than 50% for up to 2 years. Consistent association with BUN may indirectly indicate overuse of diuretics post-LVAD implant.