Retrospective evaluation of leflunomide as an adjunctive therapy in dogs with non-associative immune-mediated thrombocytopenia: 20 cases (2008-2021).

OBJECTIVE: To describe leflunomide as an adjunctive therapy in the treatment of non-associative immune-mediated thrombocytopenia. MATERIALS AND METHODS: A retrospective study of dogs with a diagnosis of non-associative immune-mediated thrombocytopenia treated with leflunomide March 2008 to September 2021 was conducted. Data collected included signalment, clinical signs, physical examination findings and diagnostic testing performed. Medications administered, duration of hospital stay, time to platelet concentration >150×109/L and adverse events during leflunomide therapy were recorded. Relapses within a year of diagnosis were reported. RESULTS: A total of 20 client-owned dogs met inclusion criteria. Nineteen of 20 dogs (95%) achieved a platelet concentration >150×109/L with leflunomide and prednisone combination therapy and four dogs (21.1%) relapsed during treatment or shortly after treatment. Adverse effects included diarrhoea (n=5), mild lymphopenia (n=9) and mild intermittent anaemia (n=1). A single dog developed hepatotoxicity presumed to be secondary to leflunomide therapy that resolved after drug discontinuation. One dog was treated for aspiration pneumonia during treatment. Two dogs were euthanased while receiving leflunomide. CLINICAL SIGNIFICANCE: Length of hospitalisation, time to platelet recovery, treatment response and relapse rate were comparable with alternative treatment protocols. Most adverse effects did not require leflunomide dose adjustment; however, two dogs died while undergoing leflunomide treatment and there is compelling evidence that one of these dogs experienced fatal infection secondary to immune-suppression. Hepatotoxicity remains a known complication of leflunomide treatment and serial biochemistry testing is recommended.

Establishing an approach for patients with recent coronary occlusion: identification of viable myocardium.

BACKGROUND: Revascularization of occluded coronary arteries after myocardial infarction (MI) may restore flow to viable myocardium and improve ventricular function. The aim of this pilot study was to determine the potential utility of thallium-201 viability imaging for the prediction of recovery of regional ventricular function in patients undergoing revascularization of total or subtotal occlusion of infarct-related arteries (TIMI 0-2 flow) during the convalescent period after MI. METHODS: Twenty-three patients were identified < 6 weeks after MI and underwent Tl-201 viability imaging (rest imaging, n = 16; stress/reinjection imaging, n = 7) and radionuclide angiography. Patients were revascularized with percutaneous transluminal coronary artery in 10, stent in 10, and bypass in 3. Follow-up radionuclide angiography at 3 months was used to assess recovery of regional wall motion. RESULTS: Among 41 abnormal wall motion segments in the infarct territories, the sensitivity, specificity, and accuracy for Tl-201 imaging in the prediction of recovery of regional function were 89% (25/28), 54% (7/13), and 78% (32/41), respectively. When 8 segments supplied by vessels with restenosis to >70% were excluded, specificity improved to 70%. Wall motion scores improved in those with adequate revascularization (1.6+/-1.4 vs 2.7+/-1.6; P < .001) but not in those with restenosis or occlusion (1.8+/-1.0 vs 2.0+/-1.6; P = NS). CONCLUSIONS: In patients with an occluded artery after MI, Tl-201 viability imaging can detect recoverable myocardium with reasonable accuracy and may help select which patients will most benefit from revascularization.

Late clinical and angiographic follow-up after stenting in evolving and recent myocardial infarction.

OBJECTIVES: This study sought to assess the late clinical and angiographic outcomes of patients who received stents within the first week of acute myocardial infarction (AMI). BACKGROUND: Recent studies have demonstrated that stenting of the infarct-related artery is a useful adjunct to balloon angioplasty in patients with AMI. However, there are limited data on the late clinical and angiographic outcomes of these patients. METHODS: Between January 1994 and September 1995, 32 patients at our institution underwent stenting of the infarct-related artery within 1 week of AMI: 13 within 14 hours (evolving group) and 19 between days 2 and 7 (recent AMI group). Late clinical follow-up was obtained on all survivors. Quantitative angiographic measurements were recorded on the stented segments before stenting, immediately after stenting, and on the follow-up angiograms. RESULTS: At 13.1+/-6.4 months from the time of stenting, three patients died and three required repeat angioplasty, but no patient had reinfarction or required bypass surgery. At follow-up 26 (81%) of 32 patients remained free of major cardiac events; of these, 24 (92%) were free of angina. Repeat angiography performed at 10.8+/-7.5 months in 26 (87%) of 30 discharged patients showed that all infarct-related arteries were patent and the restenosis rate was low: 22% in the 13 patients with evolving AMI (<14 hours) and 12% in the 19 patients with recent AMI (days 2 through 7). CONCLUSION: In this study stenting of the infarct-related artery in patients with evolving and recent AMI was associated with a favorable late clinical outcome. Patency of the infarct-related artery was well maintained, and the restenosis rate was low.

Usefulness of intracoronary stenting in acute myocardial infarction.

Data on the feasibility, safety, and clinical outcome of intracoronary stenting in acute myocardial infarction (AMI) are limited. This study examined the immediate angiographic results and the early and late outcomes in 32 patients who had stenting during AMI. Coronary angiograms recorded at the time of stenting were reviewed with quantitative measurements obtained on the "target" coronary lesion before and after stenting. Immediate angiographic success was achieved in 30 patients (94%). The minimal luminal diameter increased from 0.36 +/- 0.37 to 2.58 +/- 0.41 mm (p<0.0001). Two patients died in the hospital. Of the remainder, none had reinfarction or required bypass surgery, whereas 2 required repeat coronary angioplasty for recurrent ischemia. Although thrombus at the infarct-related coronary lesion was initially detected in 41% of the patients, its presence was not associated with adverse procedural outcome. Only 1 patient had persistent thrombus after stenting, which resolved with intracoronary urokinase. At a mean follow-up of 6.1 +/- 4.1 months, there was 1 additional cardiac death, and no patient had AMI or required repeat coronary angioplasty or bypass; among the 29 survivors, 86% were free of angina. Thus, intracoronary stenting of the infarct-related artery in the setting of AMI is associated with excellent immediate angiographic success and a favorable clinical outcome, and remains an option even in the presence of thrombus.