Bioprosthetic valve thrombosis after transcatheter aortic valve replacement and pulmonary embolism due to heparin-induced thrombocytopenia: a case report.

Background: Bioprosthetic valve thrombosis is a complication of transcatheter aortic valve replacement (TAVR). It is believed to be platelet independent, mainly driven by contact phase activation, and more likely to be targeted by oral anticoagulant (OAC). Case summary: We report case of an 86-year-old man with history of TAVR, who presented an early TAVR aortic valve thrombosis occurring in the context of heparin-induced thrombocytopenia (HIT) and pulmonary embolism. The patient rapidly recovered and was discharged 17 days after readmission. OAC by Coumadin was administered for 3 months. Chest tomography after 3 months showed the disappearance of the hypoattenuated leaflet thickening. Discussion: Although HIT has been fully described and is known for being a prothrombotic disorder, this is the first case report of aortic valve thrombosis after TAVR due to HIT. HIT is rare but possibly lethal. Diagnosis is based on pre-test probability evaluation with the 4T clinical score and confirmation with laboratory evidence of anti-PF4/heparin complexes and positivity of a functional test. Management of HIT is based on heparin discontinuation, and treatment of thrombotic complication with direct anti-IIa inhibitor or anti-Xa inhibitor. According to our knowledge, this case represents the first report of bioprosthetic valve thrombosis after TAVR due to HIT.

Outcomes of patients with active cancer undergoing transcatheter aortic valve replacement.

BACKGROUND: Cardiovascular disease and cancer are the two leading causes of mortality worldwide, and their association presents a therapeutic challenge. Current data regarding the prognosis of active cancer in patients undergoing transcatheter aortic valve replacement are conflicting. AIM: To determine the impact and prognosis of active cancer in transcatheter aortic valve replacement. METHODS: All consecutive patients with severe aortic stenosis treated by transcatheter aortic valve replacement between February 2010 and May 2019 were enrolled in a prospective study. The cohort was divided according to the presence or absence of active cancer at baseline. The primary endpoint was all-cause mortality 1 year after the procedure. RESULTS: A total of 1,125 patients were enrolled: 1,037 (92.2%) without and 88 (7.8%) with active cancer. The most frequent cancers were haematological (36.4%), breast (14.8%) and prostate (14.8%), with 79.5% of patients receiving curative treatment and 17.0% receiving palliative treatment. The 1-year mortality rate was higher in patients with active cancer (27.3% vs. 13.9%; P<0.01), mainly driven by non-cardiovascular causes. An increased cardiovascular mortality rate at 2 years was seen in patients with active cancer (27.5% vs. 15.0%; P=0.03) compared with a similar rate at 1-year follow-up. Active cancer was a strong predictor of 1-year all-cause mortality (hazard ratio 2.46, 95% confidence interval 1.19-4.68; P=0.02). Major/life-threatening bleeding events at 1 year were more frequent in patients with active cancer (P=0.02). CONCLUSIONS: Among patients who undergo transcatheter aortic valve replacement, 1-year all-cause mortality is higher in those with active cancer. We also observed a trend towards increased long-term bleeding events in case of active cancer.

The MHC class I MICA gene is a histocompatibility antigen in kidney transplantation.

The identity of histocompatibility loci, besides human leukocyte antigen (HLA), remains elusive. The major histocompatibility complex (MHC) class I MICA gene is a candidate histocompatibility locus. Here, we investigate its role in a French multicenter cohort of 1,356 kidney transplants. MICA mismatches were associated with decreased graft survival (hazard ratio (HR), 2.12; 95% confidence interval (CI): 1.45-3.11; P < 0.001). Both before and after transplantation anti-MICA donor-specific antibodies (DSA) were strongly associated with increased antibody-mediated rejection (ABMR) (HR, 3.79; 95% CI: 1.94-7.39; P < 0.001; HR, 9.92; 95% CI: 7.43-13.20; P < 0.001, respectively). This effect was synergetic with that of anti-HLA DSA before and after transplantation (HR, 25.68; 95% CI: 3.31-199.41; P = 0.002; HR, 82.67; 95% CI: 33.67-202.97; P < 0.001, respectively). De novo-developed anti-MICA DSA were the most harmful because they were also associated with reduced graft survival (HR, 1.29; 95% CI: 1.05-1.58; P = 0.014). Finally, the damaging effect of anti-MICA DSA on graft survival was confirmed in an independent cohort of 168 patients with ABMR (HR, 1.71; 95% CI: 1.02-2.86; P = 0.041). In conclusion, assessment of MICA matching and immunization for the identification of patients at high risk for transplant rejection and loss is warranted.

Delayed pulmonary embolism after COVID-19 pneumonia: a case report.

BACKGROUND: Since the onset of the COVID-19 pandemic, several cardiovascular manifestations have been described. Among them, venous thromboembolism (VTE) seems to be one of the most frequent, particularly in intensive care unit patients. We report two cases of COVID-19 patients developing acute pulmonary embolism (PE) after discharge from a first hospitalization for pneumonia of moderate severity. CASE SUMMARY: Two patients with positive RT-PCR test were initially hospitalized for non-severe COVID-19. Both received standard thromboprophylaxis during the index hospitalization and had no strong predisposing risk factors for VTE. Few days after discharge, they were both readmitted for worsening dyspnoea due to PE. One patient was positive for lupus anticoagulant. DISCUSSION: Worsening respiratory status in COVID-19 patients must encourage physicians to search for PE since SARS-CoV-2 infection may act as a precipitant risk factor for VTE. Patients may thus require more aggressive and longer thromboprophylaxis after COVID-19 related hospitalization.