Potentially reversible severe cardiac involvement in thrombotic microangiopathies with malignant hypertension.

Background: Thrombotic microangiopathy (TMA) represents a pathological response to endothelial damage, caused by genetic or acquired factors. It includes conditions like thrombotic thrombocytopenic purpura, atypical hemolytic uremic syndrome (aHUS), and secondary TMAs. Malignant hypertension can both result from and trigger TMA. This study aims to identify risk factors for severe cardiac involvement, defined as a left ventricular ejection fraction ≤ 50%, in patients with concomitant TMA and malignant hypertension, and to investigate the evolution of cardiac anomalies post-TMA remission.

Methods: We retrospectively collected data of 33 patients with TMA and malignant hypertension, admitted to our hospital between January 2014 and December 2023. Patients were followed up to monitor kidney function, blood pressure, and hematological parameters, and those with severe cardiac involvement at admission underwent repeated echocardiograms. Genetic testing for complement factors was performed to identify aHUS cases.

Results: Severe cardiac involvement was diagnosed in 9 patients, all of whom exhibited left ventricular hypertrophy and varying degrees of diastolic dysfunction and valve regurgitation. Patients with severe cardiac involvement had significantly higher interventricular septal and posterior wall thickness at admission. Over a mean follow up of 42 months, all patients with severe cardiac involvement showed recovery of left ventricular systolic function. Patients with severe cardiac involvement had a higher incidence of respiratory failure [5/9 (56%) vs 2/24 (8%) patients, p = 0.003] and kidney failure [7/9 (78%) vs 8/24 (33%) patients, p = 0.022].

Conclusions: Severe cardiac involvement in TMA associated with malignant hypertension is common but largely reversible. Early identification and tailored treatment can lead to improved outcomes. This study highlights the importance of comprehensive cardiac assessment in managing TMA patients with malignant hypertension.