Devemos adaptar as evidências internacionais ao aplicar Medicina no SUS?

Procurou-me um estudante para conversar sobre um caso clínico. Estava acompanhando um paciente masculino, idoso, com recente IAM e angioplastia com stent (não farmacológico), que desenvolveu sangramento digestivo, manifesto por melena e queda de Ht/Hb com necessidade (questionável) de transfusão de 1UI de CHAD. Não houve instabilidade hemodinâmica. Fez uma endoscopia digestiva alta tardiamente que evidenciou uma úlcera duodenal Forrester 3. O estudante contou que os antiagregantes do paciente foram suspensos e questionou: - E o stent?

Vejamos o que tem na literatura sobre esta situação?

Há um artigo recentemente publicado no Can J Gastroenterol que ilustra um pouco o cenário:

Acetylsalicylic acid use in patients with acute myocardial infarction and peptic ulcer bleeding. 2009 Sep;23(9):619-23. Background: Acetylsalicylic acid (ASA) is used in the treatment of acute myocardial infarction (AMI) but is also a risk factor for peptic ulcer disease (PUD) bleeding. Objective: To determine the factors associated with continued ASA use in patients with AMI who develop PUD bleeding. Methods: AMI patients who developed PUD bleeding during the same hospitalization at two tertiary care hospitals in Edmonton, Alberta, between January 1999 and December 2006, were evaluated retrospectively. Multivariate analysis was used to determine predictors of the primary outcome of continued ASA use during PUD bleeding. Results: A total of 102 patients were analyzed. Thirty-eight patients (37%) were continued on ASA, while 64 (63%) had ASA discontinued during their hospitalization. On multivariate regression analysis, significant predictors of continued ASA use included lowrisk ulcer stigmata on endoscopy (OR 3.7; 95% CI 1.4 to 10.2; P=0.01) and AMI requiring coronary intervention (OR 8.2; 95% CI 2.1 to 32.1; P=0.002). The mean (+/- SD) blood transfusion requirement was 3.9+/-3.6 units. The 30-day rebleeding and mortality rates were 14% and 14%, respectively. Conclusions: The continued use of ASA during AMI and PUD bleeding was variable. However, patients with low-risk ulcers and those who received coronary intervention were more likely to have ASA continued during PUD bleeding. Further studies evaluating the gastrointestinal risk of immediate ASA use in AMI with acute PUD bleeding are required.

E quais seriam as evidências para reduzir esta variabilidade?

Há um ensaio clínico randomizado fresquinho do Ann Intern Med:

Continuation of low-dose aspirin therapy in peptic ulcer bleeding: a randomized trial. Ann Intern Med. 2010 Jan 5;152(1):1-9. Background: It is uncertain whether aspirin therapy should be continued after endoscopic hemostatic therapy in patients who develop peptic ulcer bleeding while receiving low-dose aspirin. Objective: To test that continuing aspirin therapy with proton-pump inhibitors after endoscopic control of ulcer bleeding was not inferior to stopping aspirin therapy, in terms of recurrent ulcer bleeding in adults with cardiovascular or cerebrovascular diseases. Design: A parallel randomized, placebo-controlled noninferiority trial, in which both patients and clinicians were blinded to treatment assignment, was conducted from 2003 to 2006 by using computer-generated numbers in concealed envelopes. Setting: A tertiary endoscopy center. Patients: Low-dose aspirin recipients with peptic ulcer bleeding. Intervention: 78 patients received aspirin, 80 mg/d, and 78 received placebo for 8 weeks immediately after endoscopic therapy. All patients received a 72-hour infusion of pantoprazole followed by oral pantoprazole. All patients completed follow-up. Measurements: The primary end point was recurrent ulcer bleeding within 30 days confirmed by endoscopy. Secondary end points were all-cause and specific-cause mortality in 8 weeks. Results: 156 patients were included in an intention-to-treat analysis. Three patients withdrew from the trial before finishing follow-up. Recurrent ulcer bleeding within 30 days was 10.3% in the aspirin group and 5.4% in the placebo group (difference, 4.9 percentage points [95% CI, -3.6 to 13.4 percentage points]). Patients who received aspirin had lower all-cause mortality rates than patients who received placebo (1.3% vs. 12.9%; difference, 11.6 percentage points [CI, 3.7 to 19.5 percentage points]). Patients in the aspirin group had lower mortality rates attributable to cardiovascular, cerebrovascular, or gastrointestinal complications than patients in the placebo group (1.3% vs. 10.3%; difference, 9 percentage points [CI, 1.7 to 16.3 percentage points]). Limitations: The sample size is relatively small, and only low-dose aspirin, 80 mg, was used. Two patients with recurrent bleeding in the placebo group did not have further endoscopy. Conclusion: Among low-dose aspirin recipients who had peptic ulcer bleeding, continuous aspirin therapy may increase the risk for recurrent bleeding but potentially reduces mortality rates. Larger trials are needed to confirm these findings.

Observando as opiniões de experts publicadas, a tendência seria tentar não suspender pelo menos um dos antiagregantes.

Should prophylactic low-dose aspirin therapy be continued in peptic ulcer bleeding? Drugs. 2011 Jan 1;71(1):1-10.
Patients taking low-dose aspirin for cardiovascular prevention who develop an acute peptic ulcer bleeding event represent a serious challenge in clinical practice. Aspirin discontinuation is associated with increased risk of developing a new cardiovascular event, but there is little evidence on the outcomes and best management strategy in the setting of an acute ulcer bleeding event. In this clinical scenario, it is common clinical practice to interrupt aspirin treatment for various, sometimes long, periods of time.
A recent study suggests that patients with bleeding ulcers who keep taking aspirin after successful endoscopic therapy followed by high-dose intravenous pantoprazole, bolus of 80 mg followed by 8 mg/h for 3 days, have a small increase in the risk of rebleeding but a lower overall and cardiovascular 30-day mortality rate than those who stop taking aspirin treatment. Based on current, although limited, data, we propose that these patients should undergo early endoscopic therapy to control bleeding followed by a high-dose intravenous PPI, with early reintroduction of aspirin treatment within a 5-day window after the last dose. In the presence of an acute ulcer bleeding event soon after the placement of coronary stents, the risk of stent thrombosis with removal of antiplatelet therapy is very high. We believe that early therapeutic endoscopy and a high-dose intravenous PPI is advisable in order to maintain patients on dual antiplatelet therapy. Until more evidence becomes available, clinicians will have to rely on actual data and the use of common sense to select the best option for the patient.

O paciente estava estável. Disse ao estudante que compreendia a suspensão do Clopidogrel, mas que eu o teria necessariamente em AAS, a luz da evidência atual.

No entanto, deve-se levar em conta que, onde testaram isto, todo resto era feito ou poderia ser feito, se necessário, direitinho, tal como manda os books. O mundo dos estudos via de regra se distancia bastante do mundo real. E os desfechos no hemisfério lá de cima não sofrem das influências nefastas comuns à Medicina daqui de baixo.

Se a tendência é manter pelo menos o AAS (com IBP), também é verdade que se esperaria que no paciente onde optássemos por assim fazer, havendo necessidade, houvesse acesso imediato a uma nova endoscopia digestiva, a qualquer momento, no plantão noturno ou no final de semana. No hospital do estudante já não daria para garantir isto ao paciente, por exemplo. Além do que há uma relação desfavorável de enfermeiras por paciente, falta de supervisão dos residentes fora do horário comercial, entre outros problemas. Complicado e desafiador, não?

Seguir as evidências ou assumir que as driblamos por não haver condições ideais? Como pautar estas escolhas?