The impact of VKORC1-1639G > A genetic polymorphism upon warfarin dose requirement in different ethnic populations

OBJECTIVE

Published data on the association between vitamin K epoxide reductase complex 1 (VKORC1)-1639G > A polymorphism and warfarin dose requirement are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed.

METHODS AND RESULTS

Studies were identified in English-language articles by search of PubMed and Embase database (inception to July 2013). A total of 32 prospective clinical trials involving 5005 patients were identified and included for analysis. Overall, the weighted mean maintenance dosage of warfarin in patients with the -1639AA genotype decreased 2.62 mg/d compared with that in the -1639GG genotype patients (95% CI -3.10 to -2.14; P < 0.00001) when 24 eligible studies were pooled into the meta-analysis. Furthermore, significantly lower warfarin dose requirement was found in patients with GA genotype versus GG genotype (WMD, -1.32; 95% CI -1.67 to -0.96; P < 0.00001). In the subgroup analysis by ethnicity, statistically significant lower maintenance dosage of warfarin in patients with the AA genotype versus GG genotype were found in both Caucasians (WMD, -2.47; 95% CI -2.92 to -2.03; P < 0.00001) and Asians (WMD, -2.84; 95% CI -4.57 to -1.11; P = 0.001).

CONCLUSIONS

This meta-analysis indicated that the VKORC1-1639G > A genetic polymorphism is associated with the variation of interindividual warfarin dose requirement in different ethnic populations.

Modern treatment of acute mesenteric ischaemia

BACKGROUND

Diagnosis of acute mesenteric ischaemia in the early stages is now possible with modern computed tomography (CT), using intravenous contrast enhancement and imaging in the arterial and/or portal venous phase. The availability of CT around the clock means that more patients with acute mesenteric ischaemia may be treated with urgent intestinal revascularization.

METHODS

This was a review of modern treatment strategies for acute mesenteric ischaemia.

RESULTS

Endovascular therapy has become an important alternative, especially in patients with acute thrombotic superior mesenteric artery (SMA) occlusion, where the occlusive lesion can be recanalized either antegradely from the femoral or brachial artery, or retrogradely from an exposed SMA after laparotomy, and stented. Aspiration embolectomy, thrombolysis and open surgical embolectomy, followed by on-table angiography, are the treatment options for embolic SMA occlusion. Endovascular therapy may be an option in the few patients with mesenteric venous thrombosis who do not respond to anticoagulation therapy. Laparotomy is needed to evaluate the extent and severity of visceral organ ischaemia, which is treated according to the principles of damage control surgery.

CONCLUSION

Modern treatment of acute mesenteric ischaemia involves a specialized approach that considers surgical and, increasingly, endovascular options for best outcomes.

[Effects of pretreatment with metoprolol on cardiomyocyte apoptosis and caspase-8 activation after coronary microembolization in rats]

OBJECTIVE

To investigate the effects of metoprolol on cardiomyocyte apoptosis and caspase-8 activation after coronary microembolization(CME) in rats.

METHODS

Adult rats were randomly assigned into CME group (intraventricular injection of 3000 microspheres with 42 µm in diameter), sham-operated group (0.1 ml saline) and CME plus metoprolol group (pretreatment with 3 bolus metoprolol 2.5 mg/kg intravenous injection at 10 minutes interval at 30 minutes before microspheres injection, n = 15, each group). Cardiac function was evaluated by echocardiography at 6 hours post various treatments. Cardiomyocyte apoptosis was detected with TUNEL staining and the expression of caspase-3 and caspase-8 was detected with Western blot analysis.

RESULTS

Compared with sham-operated group, LVEF (72.68% ± 3.26% vs. 82.64% ± 3.43%, P < 0.05), fractional shortening (FS) (37.46% ± 2.38% vs. 42.85% ± 3.25%) and cardiac output (CO) [(0.101 ± 0.006) L/min vs. (0.162 ± 0.008) L/min] were significantly reduced while left ventricular end-diastolic diameter (LVEDd) [(6.22 ± 0.17) mm vs. (5.18 ± 0.43) mm] was significantly increased in CME group (all P < 0.05). Cardiac function [LVEF:73.94% ± 4.22%, FS:38.53% ± 2.03%, CO:(0.120 ± 0.012) L/min, LVEDd:(6.18 ± 0.27) mm] was similar in CME plus metoprolol group compared to CME group (all P > 0.05). The cardiomyocytes apoptosis rates (3.19% ± 1.23% vs. 0.18% ± 0.10%) and the levels of activated caspase-3 and caspase-8 proteins were significantly increased in CME group than in sham-operated group (all P < 0.05). The cardiomyocyte apoptosis rate (1.32% ± 0.28%) and the levels of activated caspase-3 and caspase-8 proteins were significantly lower in CME plus metoprolol group than in CME group (all P < 0.05).

CONCLUSIONS

Metoprolol pretreatment reduced post-CME myocardial apoptosis possibly through downregulating death receptor-mediated apoptotic pathway.

[Atypical primary symptom in the form of peripheral embolisation after painless myocardial infarction]

We report a case with peripheral embolisation as the primary symptom of a painless myocardial infarction with left ventricular mural thrombosis. The patient was suffering from severe pain in his leg due to arterial occlusion. Subsequent electrocardiography and echocardiography documented severe damage to the left ventricle and a big motile mural thrombosis. A coronary angiography showed subtotal occlusion of the left descending artery. Patients presenting with peripheral thromboembolic episodes should be examined for cardiac cause even in the absence of cardiac symptoms.

Saphenous vein graft interventions: strategies and devices to minimize distal embolization

Percutaneous coronary intervention of degenerated saphenous vein grafts remains relatively high risk when compared to native vessel interventions, despite advances in pharmacotherapy and embolic protection. This article discusses the phenomenon of distal embolization that seems to plague saphenous vein graft interventions, reviews device-based strategies for embolic protection, and offers a perspective on the utility of percutaneous saphenous vein graft intervention in both elective and acute settings.

[Catheter-directed thrombolytic treatment with high doses of rtPA of a lower limb ischemia complicated by peripheral embolism]

Catheter-directed thrombolytic treatment in an alternative method of treatment compared to the surgery of acute lower limbs ischemia. A case of acute lower limb ischemia due to occlusion of the vascular by-pass treated with guided thrombolysis with the use of a high doses of rtPA administered in a short period of time. Restoration of patency (revascularization) was achieved, and simultaneously complication in the form of peripheral embolism was found. After performing angioplasty of arteries occluded with embolism, total vascular revascularization and finally a very good clinical result were achieved.

[Experience in vitaprost treatment of patients with chronic abacterial prostatitis and prostatic adenoma after prostatic arteries embolism]

Pain and abnormal spermatogenesis are among symptoms deteriorating quality of life in patients with chronic prostatitis. Rectal suppositories vitaprost have no side effects, relieve pain, correct spermatogenesis. The effect of vitaprost treatment persists for 3 months and longer. Prostatic arteries embolization with vitaprost suppositories as preoperative preparation is a good alternative to surgical treatment in patients with prostatic adenoma.

[A case of advanced gastric cancer with tumor embolus in the portal vein successfully treated with S-1 and CDDP therapy]

A 50-year-old man with advanced gastric cancer and a tumor embolus in the portal vein was referred to our hospital. We diagnosed the tumor as cStage III B (cT3, cN2, cH0, P0, M0) gastric cancer, and selected neoadjuvant S-1 (80 mg/m2) and CDDP (60 mg/m2) therapy for him. After 2 courses of chemotherapy, the embolus in the portal vein disappeared. After additional chemotherapy, the primary tumor and regional lymph node revealed a partial response (PR), and judging from the results from the barium meal study, upper GI endoscopic findings and CT scan, a total gastrectomy with lymph node dissection was performed.

Sinus of Valsalva thrombosis causing peripheral embolism

A 44-year-old woman was admitted with the diagnosis of peripheral arterial emboli. Peripheral angiography demonstrated total occlusion of the popliteal artery. The obstruction was successfully resolved with a Fogarty arterial embolectomy catheter. Both transthoracic and transesophageal echocardiography showed a mobile, round thrombus in the noncoronary sinus of Valsalva. The patient did not accept surgery, and anticoagulation with warfarin was initiated. One month after treatment, transthoracic echocardiography demonstrated disappearance of the thrombus in the noncoronary sinus of Valsalva. The patient did not experience any recurrent episode of systemic embolization. This is a rare case of peripheral embolism caused by a thrombus in the noncoronary sinus of Valsalva without aneurysm.

Anticoagulation therapy for vertebral artery stump syndrome

There are very few reports describing the presence of a stump embolism after vertebral artery occlusion. We describe three patients who presented with posterior circulation ischemic strokes after vertebral artery occlusion. These patients were successfully treated with anticoagulation therapy without surgical or endovascular treatment.

[The comparison of operative and non-operative treatment for acute embolism of upper extremity artery]

OBJECTIVE

To compare surgical and non-surgical therapy of the upper extremity after acute arterial occlusion. To analyze the relation between prognosis and relevant factors of different therapeutic methods.

METHODS

Sixty patients with acute upper extremity arterial embolism treated between January 1990 and October 2007 were retrospectively studied in The First Hospital of China Medical University.

RESULTS

There were 60 patients, 32 men and 28 women, with a mean age of 63 years (21 - 86 years). Among them, 31 underwent thrombembolectomies with the Fogarty catheter and 29 received anti-coagulation and thrombolytic therapy. Therapeutic effects were evaluated by Cooley's standard. Therapeutic efficacy was better in the surgical group than in the non-surgical group (P < 0.05). There was no relationship between post-operative ischemic recovery and pre-operative ischemia severity and the site of embolism in the surgical group, while there were significant relationships in the nonsurgical group. The result of Cox proportional hazard regression model showed that the age and Cooley's standard of the patient was correlated with survival time.

CONCLUSIONS

A more active surgical approach is better for the treatment of acute arterial occlusion of the upper extremity.

Prevention and treatment of cardioembolic stroke: a case study

Ischemic stroke is a medical emergency that requires immediate evaluation and treatment. During the acute phase following stroke, the goal of therapy is reperfusion of the ischemic area with thrombolytic therapy. Blood pressure (BP) goals during the first 24 hours depend on eligibility for tissue plasminogen activator (tPA). Following the acute phase, therapy is directed at prevention of recurrent stroke with antithrombotics and control of ischemic-stroke risk factors. This is a case of a 79-year-old female with newly diagnosed atrial fibrillation who was inappropriately started on aspirin for anticoagulation despite her high risk for stroke. She subsequently suffered a cardioembolic stroke. The patient was not a candidate for tPA because of the inability to determine when symptom onset occurred. Supportive care focused on BP and glycemic control as well as venous thromboembolism prophylaxis. Secondary prevention of stroke for this patient included treatment of hypertension, diabetes, and hypercholesterolemia as well as initiation of warfarin.

[Superior mesentery artery embolization as a complication of the primary angioplasty solved by local thrombolysis]

Acute mesentery artery embolization is a rare complication of invasive catheterizations. The incidence is unknown. In case of late diagnosis the mortality may reach up to 93%. Acute abdominal pain, vomitus, rapid and sudden bowel evacuation with or without blood are the typical symptoms of the disease. Plain X-Rays of abdomen or CT tomography may show no signs of intestinal ischaemia. The diagnostic method to choose is either spiral CT angiography or contrast angiography, respectively. The most common therapeutical approach is surgical revascularization but in selected cases it is feasible to perform local thrombolysis with a microcatheter placed directly into the artery with embolus. We report a case of a man who was admitted with an acute myocardial infarction who underwent primary angioplasty with implantation ofa bare-metal stent. After the procedure he developed severe and progressive abdominal pain as a result of acute superior mesentery artery embolization. In this patient we performed a local thrombolysis with rt-PA (alteplase) with a great technical success and immediate pain relief, with no need of surgical revision. Our approach was concordant to recommendations cited in this article.

Risk factors and treatment at recurrent stroke onset: results from the Recurrent Stroke Quality and Epidemiology (RESQUE) Study

BACKGROUND

Much effort has been made to study first-ever stroke patients. However, recurrent stroke has not been investigated as extensively. It is unclear which risk factors dominate, and whether adequate secondary prevention has been provided to patients who suffer from recurrent stroke. Also, the different types of recurrent stroke need further evaluation.

METHODS

The study included patients with recurrent stroke admitted to twenty-three Swedish stroke centers. The type of previous and recurrent stroke was determined, as well as evaluation (when applicable) of recurrent ischemic stroke according to the TOAST classification. Presence of vascular risk factors was registered and compared to the type of stroke. Also assessed was ongoing secondary prevention treatment at recurrent stroke onset.

RESULTS

A total of 889 patients with recurrent stroke (mean age 77) were included in the study. Of these, 805 (91%) had ischemic stroke, 78 (9%) had intracerebral hemorrhage and 6 (<1%) stroke of unknown origin. The most frequent vascular risk factors were hypertension (75%) and hyperlipidemia (56%). Among the 889 patients, 29% had atrial fibrillation. Of the patients in the ischemic group with cardiac embolism, only 21% were on anticoagulation treatment. The majority of the patients (75%) had their most recent previous stroke >12 months before admission.

CONCLUSIONS

Few patients had a recurrent stroke shortly after the previous stroke in this study. This indicates that it is meaningful to prevent a second event with an adequate long-term treatment strategy for secondary prevention after first-ever stroke. There also seems to be a clear potential for improving secondary prevention after stroke.

Direct Thrombin Inhibition and Stroke Prevention in Elderly Patients With Atrial Fibrillation

BACKGROUND AND PURPOSE

Warfarin prevents stroke in atrial fibrillation (AF); however, concerns regarding international normalized ratio control and hemorrhage limit its use in the elderly. The oral direct thrombin inhibitors (DTIs) are potential alternatives to warfarin, offering fixed dosing without drug and dietary interactions and the need for international normalized ratio monitoring. Although ximelagatran, a DTI studied in the Stroke Prevention using an ORal Thrombin Inhibitor in atrial Fibrillation trials, has been withdrawn, development of other DTIs continues. We report our experience in elderly high-risk AF patients on ximelagatran compared with warfarin therapy.

METHODS

Data from patients with AF and stroke risk factors randomized in Stroke Prevention using an ORal Thrombin Inhibitor in atrial Fibrillation III and V trials to ximelagatran or warfarin were analyzed for stroke/systemic emboli, bleeding, and raised alanine aminotransferase levels in those >or=75 (n=2804) and <75 (n=4525) years.

RESULTS

Ximelagatran was as effective as warfarin in reducing stroke/systemic emboli in the elderly (2.23%/y with ximelagatran vs 2.27%/y with warfarin) as in younger patients (1.25%/y vs 1.28%/y). Total bleeds were significantly lower with ximelagatran compared with warfarin in elderly (40% vs 45%, P=0.01) and younger (27% vs 35%, P<0.001) patients. Raised alanine aminotransferase values (>3-fold elevation) among ximelagatran patients were more common in older (7.5% old vs 5.3% young) patients, particularly women (9.5% elderly women vs 6.1% elderly men).

CONCLUSIONS

In high-risk elderly AF patients, ximelagatran is as effective as warfarin with less bleeding, but alanine aminotransferase elevations are common, particularly in elderly women. Oral DTIs for stroke prevention show promise in elderly patients.

Cardiac Transplantation in Patients With Anti-phospholipid Antibodies

Patients with severe heart failure are known to have an increased incidence of thromboembolic events and frequently have a visible thrombus in the left ventricle. Thromboemboli in heart failure patients are usually attributed to the underlying heart failure, and alternative etiologies for thrombus formation are rarely sought. However, anti-phospholipid antibodies and other inherited or acquired clotting abnormalities may contribute to hypercoagulability in heart failure patients and can lead to a persistent high risk for clotting, even after heart transplantation has corrected the underlying heart failure. We report outcomes with heart transplantation in 3 young patients with anti-phospholipid antibodies and a history of pre-heart transplantation thromboembolic events, and demonstrate the importance of post-heart transplantation anti-coagulation in these patients.