The Use of Intraprocedural Reinfusion During MitraClip Implantation to Reduce Blood Loss and Transfusion Requirements

Abstract: Background. MitraClip implantation has been shown to reduce mitral regurgitation and is an effective treatment option for patients at high risk for conventional surgery. Blood loss is common during the procedure. We assessed the utility of intraprocedural reinfusion of blood aspirated during MitraClip implantation. Methods. We compared hemoglobin before and after MitraClip implantation and transfusion requirements in patients who did (n = 83) and did not receive reinfusion (n = 31) during their procedure. For patients who received reinfusion, blood removed during device manipulation was carefully injected back into the patient through the 24 Fr delivery sheath, followed by a saline flush. Results. As expected, patients who received reinfusion had a smaller reduction in hemoglobin post procedure compared to those who did not (0.96 ± 1.0 g/dL vs 1.55 ± 0.94 g/dL; P<.01). There was a trend to lower requirements for blood transfusion in the reinfusion groups (0.39 ± 0.96 units/patient vs 0.15 ± 0.53 units/patient; P<.10). At 30-day follow-up, there was no difference in mortality, stroke, endocarditis, or thromboembolic events between groups. Conclusion. Reinfusion of aspirated blood during MitraClip was associated with reduced blood loss and a trend to reduced requirement for blood transfusion post procedure. Reinfusion during the procedure appeared safe, with no complications.

J INVASIVE CARDIOL 2018;30(1):E1-E3.

Key words: MitraClip, transfusion, safety, mitral regurgitation

Edge-to-edge mitral valve repair using the MitraClip (Abbott Vascular) has been shown to effectively reduce mitral regurgitation (MR) with significant improvement in functional capacity post procedure.¹ Patients undergoing MitraClip are typically high risk for surgical repair or valve replacement.²  The procedure uses large-bore access (24 Fr) and manufacturer recommendation includes continuous withdrawal of blood from the delivery sheath during dilator and delivery system removal to reduce risk of air embolus into the left atrium. This withdrawal technique results in blood loss, which may worsen symptoms of dyspnea and may require blood transfusion. Blood transfusion is associated with a small but significant risk of serious adverse events.³ Over 10% of patients in the Endovascular Valve Edge-to-Edge Repair (EVEREST-II) trial required transfusion of more than 2 units of blood intraprocedurally or over the immediate postoperative period following MitraClip,¹ while registry data reported major bleeding in 3% of patients.² 

We report the safety and efficacy of manual reinfusion following MitraClip device manipulation to reduce requirement for blood transfusion post MitraClip in a consecutive series of patients.

Methods

We compared hemoglobin pre and post MitraClip and transfusion requirements in 115 consecutive patients who received (n = 83 patients) and did not receive (n = 32 patients) reinfusion of aspirated blood during their procedure. 

Transcatheter mitral valve repair was performed using the MitraClip under general anesthesia. Transseptal puncture was performed using standard techniques; the interatrial septum was sequentially dilated and the MitraClip steerable sheath was positioned in the left atrium. The procedure was performed under full heparinization, maintaining an activated clotting time of ≥300 sec. The MitraClip(s) were carefully deployed under transesophageal echocardiographic and fluoroscopic guidance using a standardized technique. If ≥ moderate residual mitral regurgitation (MR) was present after deployment of the first MitraClip, a second device was placed if feasible.

For patients who received reinfusion, blood removed during device manipulation was carefully injected back into the patient through the steerable sheath immediately after aspiration, followed by a saline flush. Volume of blood was typically 100-200 mL in total, depending on number of clips inserted and procedural complexity.

Follow-up. Changes in hemoglobin, transfusion rates, and adverse events were assessed during the inpatient stay. Vital status was assessed at 30 days and for any fatalities, cause of death was assessed from detailed assessment of clinical records and autopsy where available. Follow-up was performed at 30 days in all living patients. A clinician performed a full history and examination, including record of all adverse events, including unscheduled cardiac admission, stroke, thromboembolism, and endocarditis.

Statistical analysis. Statistical analysis was performed using SPSS version 19. Data were presented as mean ± standard deviation for normally distributed data and compared using t-tests. Non-parametric data were presented as median (interquartile range [IQR]) and compared using the Mann-Whitney U-test where appropriate. Categorical variables were compared using the Chi-square test. A P-value of <.05 was considered significant.

Results

A total of 114 patients underwent MitraClip procedure. Patients were elderly (mean age, 80 ± 9 years) and considered high risk for surgical intervention. The mean STS score was 10.2 ± 6.5. Eighty-three patients received reinfusion of aspirated blood and 31 patients did not receive reinfusion during the procedure. MitraClip insertion was successful in all cases. Patient and procedural characteristics are described in Table 1. 

Postprocedure hemoglobin and transfusion requirements. Hemoglobin drop was less in patients who received reinfusion compared to those who did not (median 0.7 g/dL [IQR, 1.1 g/dL] vs 1.7 g/dL [IQR, 1.5 g/dL]; P<.01) (Figure 1). There was a trend to lower requirements for blood transfusion in the reinfusion groups (0.39 ± 0.96 units/patient vs 0.15 ± 0.53 units/patient; P=.10) (Figure 2)  despite a lower baseline hemoglobin in the reinfusion group (P=.03). 

Thirty-day follow-up. At 30-day follow-up, 6 patients had an acute unscheduled cardiac admission. There were no strokes, endocarditis, or thromboembolic events in either group. There were no fatalities. 

Discussion

Immediate reinfusion of blood aspirated during MitraClip procedures appeared safe, with no postprocedural stroke or thromboembolism. As expected, reinfusion was associated with a smaller drop in hemoglobin post procedure and there was a trend to reduced requirements for blood transfusion post procedure.

Patients undergoing MitraClip are often elderly with multiple co-morbidities. The procedure is usually well tolerated; however, significant volumes of blood (up to 200 mL) can be withdrawn during manual aspiration as equipment is removed. Avoiding acute blood loss during MitraClip implantation is desirable as anemia will exacerbate symptoms of MR, increase cardiac output, and confound gradients across the mitral valve during the procedure. 

We report a simple technique of reinfusion of blood aspirated during de-airing of the MitraClip sheath. This was well tolerated with no complications at 30-day follow-up. In particular, there were no stroke or thrombotic events. Although cell salvage may be employed for larger volumes of blood loss in surgical procedures, it results in extra cost and complexity and is not commonly used in the cardiac catheterization laboratory. 

Is there a risk of reinfusion without filtration of aspirated blood? The theoretical concerns about this technique are risk of reintroduction of unfiltered blood, including activated platelets and plasma proteins. For this reason, cell salvage autotransfusion systems employed during major surgery usually filter or centrifuge blood prior to autotransfusion of the filtered blood.⁴ These techniques are usually used in the context of acute hemorrhage suctioned from the surgical site and acute cytokine release may not occur in reinfusion of blood from other sites.⁵

In contrast to surgical practice, in the catheterization laboratory, reinfusion of freshly aspirated blood back through the catheter system is commonly performed, particularly in pediatric and congenital heart disease during right heart catheterization saturation runs. Although this is common practice, to our knowledge, this is the first case series to formally report the safety of this technique. We demonstrated that reinfusion of unfiltered blood straight after aspiration while the patient is fully heparinized is safe and not associated with risk of thrombosis or other adverse events. The technique did not add significantly to the procedure time. While non-significant, there was a trend toward lower rates of requirement for blood transfusion post procedure in the reinfusion cohort.

Conclusion

Reinfusion during MitraClip implantation was associated with reduced blood loss and a trend to reduced requirement for blood transfusion post procedure. Reinfusion was safely performed in our cohort, with no evidence of adverse events. It is now the routine standard of care at our institution during MitraClip procedures.

References

1.    Feldman T, Foster E, Glower DD, et al; EVEREST II Investigators. Percutaneous repair or surgery for mitral regurgitation. N Engl J Med. 2011;364:1395-1406. 

2.     Sorajja P, Mack M, Vemulapalli S, et al. Initial experience with commercial transcatheter mitral valve repair in the United States. J Am Coll Cardiol. 2016;67:1129-1140. 

3.     Cho J, Choi SJ, Kim S, Alghamdi E, Kim HO. Frequency and pattern of non-infectious adverse transfusion reactions at a tertiary care hospital in Korea. Ann Lab Med. 2016;36:36-41. 

4.     Nitescu N, Bengtsson A, Bengtson JP. Blood salvage with a continuous autotransfusion system compared with a haemofiltration system. Perfusion. 2002;17:357-362. 

5.     Schmidt H, Bendtzen K, Mortensen PE. The inflammatory cytokine response after autotransfusion of shed mediastinal blood. Acta Anaesthesiol Scand. 1998;42:558-564.

From the Mayo Clinic, Rochester, Minnesota.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted June 3, 2017 and accepted June 9, 2017. 

Address for correspondence: Dr Mackram F. Eleid, Department of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905. Email: eleid.mackram@mayo.edu