Anticoagulation Control in Patients With Ventricular Assist Devices

Area of Science:

• Cardiovascular Surgery
• Hematology
• Medical Device Technology

Background:

• Anticoagulation management is critical for patients with left ventricular assist devices (LVADs).
• Suboptimal anticoagulation control is linked to increased risks of thromboembolism and hemorrhage.
• Previous studies have not extensively evaluated the impact of specific anticoagulation control metrics on these adverse events in LVAD patients.

Purpose of the Study:

• To investigate the relationship between the percentage of time spent in the target international normalized ratio (INR) range (PTTR) and the risk of thromboembolism and hemorrhage in LVAD patients.
• To assess the adequacy of anticoagulation control in continuous flow LVAD recipients.

Main Methods:

• Retrospective analysis of 115 patients (≥19 years) with continuous flow LVADs implanted between 2006 and 2012.
• Estimation of PTTR for INR target range of 2.0-3.0, categorized as PTTR > 60%, PTTR ≥ 50% to < 60%, and PTTR < 50%.
• Statistical assessment of the association between PTTR categories and the incidence of thromboembolism and hemorrhage, adjusting for covariates.

Main Results:

• Only 20% of LVAD patients achieved the target anticoagulation control (PTTR > 60%).
• Patients with PTTR ≥ 60% had a significantly lower relative risk of thromboembolism (HR: 0.37) and hemorrhage (HR: 0.45) compared to those with PTTR < 50%.
• No significant reduction in risk was observed for patients with PTTR between 50% and 60%.

Conclusions:

• LVAD patients, on average, spend only 42.9% of the time within the recommended INR target range.
• Achieving a PTTR greater than 60% is associated with significantly reduced risks of both thromboembolism and hemorrhage in LVAD recipients.
• This study highlights the importance of optimizing anticoagulation control in LVAD patients to improve clinical outcomes.