Clinical outcomes associated with anti-coagulant therapy in patients with renal infarction

A Case of Recurrent Renal Infarction Following Transient Resolution: Evidence From Serial Computed Tomography

Although renal infarction (RI) is not a rare disease, its outcomes have not been well-documented. Furthermore, transient resolution and recurrence of RI have not been captured through imaging. We report a case of idiopathic RI that recurred within a short period following transient resolution, as demonstrated by serial computed tomography (CT). A 53-year-old man diagnosed with RI was transferred to the emergency room. An abdominal CT scan at the local hospital revealed a segmental wedge-shaped perfusion defect in the left kidney and a focal thrombotic filling defect in the anterior segmental branch of the left renal artery. Since his left flank pain improved, another CT scan was performed again 6 hours after the initial CT scan. A repeat CT scan showed that the thrombus in the renal artery remained, but the perfusion defect had spontaneously resolved. We initiated anticoagulant therapy using unfractionated heparin. On the sixth day of hospitalization, the left flank pain recurred, prompting another CT scan. The follow-up CT scan confirmed that RI had recurred in the same area as before. We continued anticoagulant therapy and switched to warfarin. After treatment, his symptoms improved, and he was discharged. RI can recur at any time, even after it has spontaneously resolved, as evidenced by our case. Therefore, it is crucial to closely monitor patients who experience resolution of RI for any recurrence of symptoms, and repeat radiological evaluation should be performed even within a short period.

Renal artery infarction in the SARS-Cov-2 era: A systematic review of case reports

AIM

Renal artery infarction (RI) is the presence of blood clot in the main renal artery or its branches causing complete or partial obstruction of the blood supply. Its etiology is either related with disorders of the renal vasculature or with cardiovascular diseases. Recently, the SARSCoV- 2 virus is an emerging cause of thromboembolic events and the incidence of RI is anticipated to increase after the pandemic.

METHODS

A systematic review based on COVID-19 associated RI was conducted.

PROTOCOL

A systematic review of the Medline/Pubmed and Scopus databases was conducted in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (the PRISMA statement). Search strategy and information sources: A hand-search was performed using the terms "SARS-Cov-2" OR "COVID-19" AND "renal thrombosis" OR "renal infarction" OR "renal "thromboembolism".

ELIGIBILITY CRITERIA

all types of publications (case reports, case series, letters to the editor, short communications) were evaluated for relevance. Inclusion criteria were: confirmed SARS-Cov-2 infection irrespectively of the age, diagnosis of RI during or after the onset of viral infection, and exclusion of other potential causes of thromboembolic event except of SARS-Cov-2. Patients with renal transplantation were also considered. Study criteria selection: after checking for relevance based on the title and the abstract, the full texts of the selected papers were retrieved and were further evaluated. Duplicated and irrelevant cases were excluded. Any disagreement was resolved by consensus with the involvement of a third reviewer. Quality of studies: The assessment of the quality case reports was based on four different domains: selection, ascertainment, casualty and reporting. Each paper was classified as "Good", "Moderate" and "Poor" for any of the four domains. Data extractions: Crucial data for the conduct of the study were extracted including: age, sex, time from SARS-Cov-2 infection till RI development, medical history, previous or current antithrombotic protection or treatment, laterality and degree of obstruction, other sites of thromboembolism, treatment for thromboembolism and SARS-Cov-2 and final outcome.

DATA ANALYSIS

methods of descriptive statistics were implicated for analysis and presentation of the data.

RESULTS

The systematic review retrieved 35 cases in 33 reports. In most cases, RI was diagnosed within a month from the SARSCov- 2 infection albeit 17 out of 35 patients were receiving or had recently received thromboprophylaxis. Right, left, bilateral and allograft obstruction was diagnosed in 7, 15, 8 and 5 patients respectively. 17 cases experienced additional extrarenal thromboembolism primarily in aorta, spleen, brain and lower limbs. Low molecular weight heparins (LMWH) (usually 60-80 mg enoxaparine bid) was the primary treatment, followed by combinations of unfractionated heparin and salicylic acid, apixaban and rivaraxaban, warfarin, acenocoumarol or clopidogrel. Kidney replacement therapy was offered to five patients while invasive therapies with thrombus aspiration or catheter directed thrombolysis were performed in two. Regarding the outcomes, five of the patients died. The total renal function was preserved in 17 cases and renal impairment with or without hemodialysis was recorded in 5 patients, two of them having lost their kidney allografts.

LIMITATIONS

The majority of included studies are of moderate quality. The results and the conclusions are based on case-reports only and crucial data are dissimilarly presented or missing through the relevant publications.

CONCLUSIONS

Thromboprophylaxis may not offer adequate protection against SARS-Cov-2 induced thrombosis. Most patients could be effectively treated with conservative measures, while in more severe cases aggressive treatment could be recommended.

IMPLICATIONS OF KEY FINDINGS

Therapeutic doses of LMWH could be considered for protection against RI in SARS-Cov-2 cases. Interventional treatment could be offered in a minority of more severe cases after carful balancing the risks and benefits.

A Case Report of a Young Female With Renal Infarction Secondary to Breakthrough COVID Infection

COVID-19 infection is a disease that induces a hypercoagulable state that appears to be more aggressive than other conditions related to endothelial damage. The kidney, a highly vascularized organ rich in Angiotensin-Converting Enzyme 2 (ACE2) receptors, is commonly affected by COVID-19 infection. Acute kidney injury (AKI) is common in these patients and has been linked to worse outcomes. Furthermore, kidney infarction, although uncommon, has also been reported. We present the case of a 21-year-old otherwise healthy female presenting with flank pain who was found to have renal infarction in the setting of breakthrough COVID-19 infection and Oral contraceptive pill (OCP) use. Despite getting appropriate vaccination, the patient was infected. She was not hypoxic, and her kidney function was preserved. CT angiography demonstrated peripheral hypoattenuation in the right kidney compatible with infarct but no evidence of a thrombus. The patient was medically managed with anticoagulation, and supportive therapy was offered for pain control. She had clinical improvement. The follow-up at three weeks showed normal renal function. She was continued with novel oral anticoagulation (NOAC). This case demonstrates that COVID-19 infection may present renal infarction in otherwise healthy young individuals even after appropriate vaccination. Early recognition is essential so that appropriate therapy can be given. Long-term anticoagulation and outcomes of this entity must be studied.

Case Report: Acute Renal and Splenic Infarctions Secondary to Atrial Fibrillation

Acute renal and splenic infarctions are an uncommon condition that can result from obstruction or decrease of renal and splenic arterial flow. We described a 73-year-old woman who presented with right flank pain and nocturnal dyspnea. The computed tomography (CT) scan with intravenous contrast showed multiple infarcts in both bilateral kidneys and spleen. Serum creatinine clearance was impaired. Further investigation by electrocardiogram (ECG) and 24-h Holter revealed that the patient had paroxysmal atrial fibrillation (PAF). Transthoracic and transesophageal echocardiographic findings were unremarkable except for severe spontaneous echo contrast (SEC) in the left atrial appendage. The development of thromboembolic renal and splenic infarction was attributed to embolism caused by atrial fibrillation. Anticoagulant therapy was initiated with low molecular weight heparin (LMWH) and followed by an oral anticoagulant. To manage PAF and prevent further embolism, the “One-stop” procedure, including atrial fibrillation catheter ablation and left atrial appendage occlusion (LAAO), was applied to this patient. Follow-up at 1 month showed normal sinus rhythm, improved renal function, and relieved renal and splenic infarction.

Renal arteriography with endovascular ultrasound for the management of renal infarction patients

Background

Renal infarction (RI) is a rare disease with poor prognosis. Appropriate secondary prevention treatment is essential and requires an exhaustive etiological assessment. We aimed to determine whether invasive endovascular explorations may improve the diagnostic process and change the secondary prevention treatment strategy in RI patients.

Methods

We report a retrospective observational study of 25 RI patients referred to Tours University Hospital between 2011 and 2018 for etiological investigation including renal arteriography and intravascular ultrasonography (IVUS). We sought for antithrombotic treatment regimen, vital status, bleeding and ischemic outcomes during the median follow-up of 59 months.

Results

Invasive explorations showed local arterial disease in 14 patients (56%). This led to a diagnosis or change in diagnosis in 9 patients (36%) and to a change in antithrombotic strategy in 56% of cases, with an increased prescription of antiplatelet therapy. No patient died, only two patients (8%) had persistent mild renal insufficiency. One IVUS complication was reported and treated without any significant long-term consequences.

Conclusion

Invasive endovascular investigations of RI may modify the secondary prevention treatment through a better assessment of the aetiology of RI. Multicentric randomized studies are necessary to advocate the hypothesis that invasive exploration of renal artery can improve long-term prognosis.

Acute renal and splenic infarctions: a review

BACKGROUND

Renal and splenic infarctions are close entities, with few data concerning their clinical, biological and radiological features.

AIM

The aim of this study was to compare the clinical presentations, etiologies and outcomes of acute renal infarctions (RI) and splenic infarctions (SI).

DESIGN

A retrospective multicentric cohort study included patients of the 6 university hospitals in Lyon with RI, SI, or associated RI-SI infarctions was conducted.

METHODS

All consecutive cases diagnosed by CT imaging, between January 2013 and October 2016, were included. The exclusion criteria were causes of infarction that did not require additional investigations.

RESULTS

A total of 161 patients were selected for analysis: 34 patients with RI, 104 patients with SI and 23 patients with both RI-SI. Mean ± SD age of patients was 63.2 ± 16.6 years; 59.6% were male. Only 5/161 (3.1%) were healthy prior to the event. The main symptoms were diffuse abdominal pain (26.4%), followed by nausea/vomiting (18.3%) and fever (16.4%).The causes of RI or SI varied significantly within the three groups. Hypercoagulable state was associated with SI, and embolic disease and arterial injury were associated with RI. Extensive (i.e.>2/3 of organ volume) (OR 6.22, 95%CI 2.0119.22) and bilateral infarctions (OR 15.05, 95%CI 1.79-126.78) were significantly associated with hemodynamic shocks. The survival at 1 month follow-up did not significantly differ between the three groups.

CONCLUSION

Acute RI and SI are heterogenous entities in regards to their clinical presentation, etiology, associated venous or arterial thrombosis, but prognoses were not different at short term follow-up.