Roberto Abi Rached

Hemostatic changes and clinical sequelae after on-pump compared with off-pump coronary artery bypass surgery: a prospective randomized study

ObjectiveTo delineate the effects of extracorporeal bypass on biomarkers of hemostasis, fibrinolysis, and inflammation and clinical sequelae. MethodsPatients were assigned prospectively and randomly to either on-pump (n=41) or off-pump (n=51) coronary bypass surgery. The concentrations of C-reactive protein, fibrinogen, D-dimer, and plasminogen activator inhibitor type-1 in blood were quantified before and after (1 and 24 h) surgery. Similar surgical and anesthetic procedures were used for both groups. Clinical events were assessed during initial hospitalization and at the end of 1 year. ResultsThe concentrations of plasminogen activator inhibitor type-1 and D-dimer were greater compared with preoperative values 1 and 24 h after surgery in both groups, but their concentrations increased to a greater extent 24 h after surgery in the on-pump group (P<0.01). The concentration of C-reactive protein did not change appreciably immediately after surgery in either group but increased in a parallel manner 24 h after either on-pump or off-pump surgery (P<0.01). Bypass surgery in the on-pump group was associated with greater blood loss during surgery and more bleeding after surgery (P≤0.01). The incidence of all other complications was similar in the two groups. ConclusionOn-pump surgery was associated with biochemical evidence of a prothrombotic state early after surgery but no greater incidence of thrombotic events was observed. The prothrombotic state might be a consequence of extracorporeal bypass, compensation in response to more bleeding, or both in patients undergoing on-pump surgery.

Prevention of Venous Thrombosis by Warfarin after Permanent Transvenous Leads Implantation in High-Risk Patients

Background: The incidence of venous lesions following transvenous cardiac device implantation is high. Previous implantation of temporary leads ipsilateral to the permanent devices, and a depressed left ventricular ejection fraction have been associated with an increased risk of venous lesions, though the effects of preventive strategies remain controversial. This randomized trial examined the effects of warfarin in the prevention of these complications in high‐risk patients.

Comparison between international normalized ratio using a portable device and conventional methodology.

OBJECTIVE to compare the international normalized ratio (INR) measured by a point-of-care (POC) testing device with that measured by the conventional method in patients undergoing anticoagulation therapy with warfarin sodium. METHODS The INR of 383 warfarin-treated patients (mean age: 56.5 years; 207 female) was measured in capillary blood using the Hemochron Jr. device and compared with that of venous plasma samples determined by the conventional method performed in a Coag-A-Mate analyzer. Results were evaluated globally and for the following subgroups: INR < 2.0, from 2.0 to 3.5, and > 3.5. RESULTS Using both methods, the comparison between INR values yielded a correlation coefficient (r) of 0.86. However, mean differences in INR in both tests, considering the three subgroups, proved to be statistically significant (p <0.001): 0.14 +/- 0.21 (INR< 2.0); 0.54 +/- 0.31 (2.0 < or = INR < or = 3.5), and 1.64 +/- 1.10 (INR> 3.5). Paired Students t-test analysis revealed a p value < 0.001 for the three subgroups studied. CONCLUSION The use of point-of-care testing for monitoring oral anticoagulation has some limitations. Anticoagulation intensity was underestimated by this method in the three subgroups studied.

Warfarin prevents venous obstruction after cardiac devices implantation in high-risk patients: partial analysis

OBJECTIVES To evaluate the efficacy of prophylactic use of warfarin in patients with high risk of lead-associated thrombosis. METHODS Clinical, prospective, randomized and blinded study, in patients submitted to first transvenous leads implantation with LVEF <0.40 and/or previous ipsilateral temporary pacing. After device implantation, patients were randomly assigned to placebo or warfarin. Periodical clinical and laboratorial evaluations were performed to anticoagulant management. After a six-month period, every patient was submitted to a digital subtraction venography. From February 2004 to November 2006, 101 patients underwent randomization. Baseline characteristics were similar in both groups (P=NS). RESULTS Venographic analysis showed 31.4% of venous obstructions in patients assigned to warfarin as compared with 57.1% in patients assigned to placebo (RR= 0.57 [95% CI, 0.33 to 0.98]; P=0.015). In the warfarin group, 72% of the PT/INR tests were in therapeutic INR range. Only one patient required warfarin discontinuation and cross-over to placebo group due to gastrointestinal bleeding. CONCLUSIONS These preliminary results showed that the anticoagulation therapy has been safe and reduced the frequency of venous thrombosis after transvenous cardiac devices implantation in high risk patients.

Update on chronic nonspecific lower back pain: rehabilitation

1. What is the benefit of acupuncture in the treatment of chronic nonspecific lower back pain? a. The performance of acupuncture combined with other conservative therapies is not more beneficial than applying the same therapies in isolation b. Real acupuncture (deep insertion into acupoints) is superior to sham acupuncture (superficial insertion at sites away from the acupoints) c. Acupuncture is less effective than TENS d. Acupuncture is less effective than massage