Major Bleeding During HeartMate II Support
Objectives The aim of this study was to characterize a single-center experience of major bleeding complications during HeartMate II (HMII) (Thoratec Corp., Pleasanton, California) left ventricular assist device support, with focus on the subtypes and temporal patterns of post-operative bleeding.
Background Bleeding complications are the most common post-operative adverse events after HMII implantation. The timing of bleeding events, relationship to coagulation status, and effect on post-operative survival are incompletely understood.
Methods From October 2004 to June 2010, 139 HMII recipients at the Cleveland Clinic received 145 devices as a bridge to transplant or destination therapy for advanced heart failure. Major bleeding was defined using Interagency Registry for Mechanically Assisted Circulatory Support criteria, with an additional category created to maximize sensitivity for events. Pre-operative variables, coagulation status, and bleeding recurrence were assessed for correlation to primary events using modulated renewal within a multivariable analysis.
Results The cumulative occurrence of major bleeding was 58% during 171 patient-years of follow-up. There were 1.14 major bleeds per patient-year, with 44% occurring as repeat bleeding events. A first bleed did not predict subsequent bleeding. The greatest risk of bleeding was noted within 2 weeks post-implantation. The international normalized ratio profile correlated poorly with the risk of bleeding. Bleeding early after surgery was associated with reduced survival while on HMII support.
Conclusions The risk of bleeding peaks early after HMII implantation. Bleeding of thoracic and gastrointestinal sources dominates these events, although many patients undergo transfusions for anemia without an apparent source of hemolysis or bleeding.
Despite advances in mechanical circulatory support, bleeding remains the most common adverse event after implantation of the HeartMate II (HMII) (Thoratec Corp., Pleasanton, California) ventricular assist device. Post-implantation bleeding complications diminish the overall effectiveness of HMII in treating advanced heart failure as a bridge to transplant (BTT). Transfusion-related bleeding represents a decidedly ominous problem; the deleterious effect of red blood cell transfusion on HMII recipient survival has been well described. With growing use of the HMII as destination therapy, bleeding rates among this population are comparatively higher relative to cohorts who receive an implant as a BTT. Therefore, efforts to reduce the rate of bleeding are imperative and urgently needed.
Bleeding complications are complex and dynamic phenomena that are likely dependent on many pre-operative and post-operative factors. From our clinical experience, some HMII recipients experience numerous bleeding events, whereas many others have none at all. Available reports that characterize HMII-related bleeding are often limited by variable bleeding definitions across studies, restricted characterization of bleeding subtypes, and heterogeneous inclusion of non-HMII devices. Accordingly, broad conclusions about post-HMII bleeding have been challenged by variability in post-operative management over time and across centers. Currently available HMII registries offer insufficient detail to account for features of bleeding complications. Whether the temporal patterns of bleeding, sources of blood loss, and impact of recurrent bleeding contribute to future events is not well understood. Therefore, we performed a detailed examination of post-HMII bleeding to address these limitations while providing novel insights that might direct future HMII care.
The aims of this study were to: 1) characterize the timing and subtypes of post-operative major bleeding after HMII implantation using standardized Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) definitions for these events while using time-sensitive modeling techniques; 2) determine the influence of coagulation status on subsequent risks for bleeding; and 3) assess the association of bleeding events on post-surgical mortality.
Abstract and Introduction
Abstract
Objectives The aim of this study was to characterize a single-center experience of major bleeding complications during HeartMate II (HMII) (Thoratec Corp., Pleasanton, California) left ventricular assist device support, with focus on the subtypes and temporal patterns of post-operative bleeding.
Background Bleeding complications are the most common post-operative adverse events after HMII implantation. The timing of bleeding events, relationship to coagulation status, and effect on post-operative survival are incompletely understood.
Methods From October 2004 to June 2010, 139 HMII recipients at the Cleveland Clinic received 145 devices as a bridge to transplant or destination therapy for advanced heart failure. Major bleeding was defined using Interagency Registry for Mechanically Assisted Circulatory Support criteria, with an additional category created to maximize sensitivity for events. Pre-operative variables, coagulation status, and bleeding recurrence were assessed for correlation to primary events using modulated renewal within a multivariable analysis.
Results The cumulative occurrence of major bleeding was 58% during 171 patient-years of follow-up. There were 1.14 major bleeds per patient-year, with 44% occurring as repeat bleeding events. A first bleed did not predict subsequent bleeding. The greatest risk of bleeding was noted within 2 weeks post-implantation. The international normalized ratio profile correlated poorly with the risk of bleeding. Bleeding early after surgery was associated with reduced survival while on HMII support.
Conclusions The risk of bleeding peaks early after HMII implantation. Bleeding of thoracic and gastrointestinal sources dominates these events, although many patients undergo transfusions for anemia without an apparent source of hemolysis or bleeding.
Introduction
Despite advances in mechanical circulatory support, bleeding remains the most common adverse event after implantation of the HeartMate II (HMII) (Thoratec Corp., Pleasanton, California) ventricular assist device. Post-implantation bleeding complications diminish the overall effectiveness of HMII in treating advanced heart failure as a bridge to transplant (BTT). Transfusion-related bleeding represents a decidedly ominous problem; the deleterious effect of red blood cell transfusion on HMII recipient survival has been well described. With growing use of the HMII as destination therapy, bleeding rates among this population are comparatively higher relative to cohorts who receive an implant as a BTT. Therefore, efforts to reduce the rate of bleeding are imperative and urgently needed.
Bleeding complications are complex and dynamic phenomena that are likely dependent on many pre-operative and post-operative factors. From our clinical experience, some HMII recipients experience numerous bleeding events, whereas many others have none at all. Available reports that characterize HMII-related bleeding are often limited by variable bleeding definitions across studies, restricted characterization of bleeding subtypes, and heterogeneous inclusion of non-HMII devices. Accordingly, broad conclusions about post-HMII bleeding have been challenged by variability in post-operative management over time and across centers. Currently available HMII registries offer insufficient detail to account for features of bleeding complications. Whether the temporal patterns of bleeding, sources of blood loss, and impact of recurrent bleeding contribute to future events is not well understood. Therefore, we performed a detailed examination of post-HMII bleeding to address these limitations while providing novel insights that might direct future HMII care.
The aims of this study were to: 1) characterize the timing and subtypes of post-operative major bleeding after HMII implantation using standardized Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) definitions for these events while using time-sensitive modeling techniques; 2) determine the influence of coagulation status on subsequent risks for bleeding; and 3) assess the association of bleeding events on post-surgical mortality.