Prognostic implications of bundle branch block in patients undergoing primary coronary angioplasty in the stent era

Clinical Predictors of Heart Failure after STEMI: Data from a Middle-Income Country with Limited Access to Percutaneous Coronary Intervention

BACKGROUND

Heart failure (HF) is a common complication of ST-elevation myocardial infarction (STEMI) in low- and middle-income countries (LMICs), where cardiovascular mortality is disproportionately high. Primary percutaneous coronary intervention (PCI) has reduced post-STEMI HF incidence in high-income countries. However, access to this standard of care is poor in LMICs, and data in these settings remain scarce.

OBJECTIVE

To identify predictors of HF following STEMI in a LMIC with limited access to PCI, aiming at better management and outcomes.

METHODS

This retrospective cohort study analyzed 2,467 STEMI patients admitted to two Brazilian public hospitals between January/2015 and February/2020. All participants received pharmacological thrombolysis and underwent coronarography within 48h post-admission. The primary outcome was symptomatic HF, defined as dyspnea with chest X-ray evidence of congestion, from 48h post-admission until discharge. Stepwise binary logistic regression was used to identify HF predictors. Significance was defined as p-values<0.05.

RESULTS

The population was 61.9% male, mean age was 58.3±12.6 years, and 39.9% developed post-STEMI HF. HF was more common among older men with cardiovascular-kidney-metabolic (CKM) disease, larger infarcts, and left anterior descending artery involvement. Medications were often underprescribed at discharge, especially aldosterone antagonists (11.0%). HF was notably more frequent among individuals with failed thrombolysis (47.0%).

CONCLUSIONS

This regionally representative cohort from a LMIC with limited access to PCI showed that older men with CKM disease are particularly vulnerable to post-STEMI HF, and that HF pharmacotherapy at discharge needs optimization. The high HF incidence among patients with failed thrombolysis highlights the need to expand PCI availability.

Association between new-onset right bundle branch block and primary or secondary ventricular fibrillation in ST-segment elevation myocardial infarction

AIMS

New-onset right bundle branch block (RBBB) in myocardial infarction (MI) is often associated with ventricular fibrillation (VF) but the nature of this relationship has not been determined.

METHODS AND RESULTS

Between 1998 and 2014, among other data, incidence and duration of RBBB and VF occurrence were prospectively collected in 5301 patients with ST-segment elevation MI (STEMI) admitted to two University Hospitals in Murcia (Spain). Multinomial adjusted logistic regression analyses were used to examine the association between RBBB, attending to its duration, and VF according to its primary VF (PVF) or secondary VF (SVF) character. Among 284 (5.4%) patients with new-onset RBBB, 158 were transient and 126 permanent. VF occurred in 339 (6.4%) patients, 201 PVF and 138 SVF, documented within the first 2 h of symptoms-onset in 78% and 60%, respectively. New-onset RBBB was more frequent in PVF (11.4%) and SVF (20.3%), than in non-VF (4.7%). Transient RBBB incidence was higher in PVF (9.0%) and SVF (9.4) than in non-VF (2.6%), whereas permanent RBBB was higher in SVF (10.9%) than PVF (2.5%) and non-VF (2.1%). New-onset RBBB 1.83 [95% confidence interval (CI): 1.07-3.11] and new-onset transient RBBB 2.39 (95% CI: 1.32-4.32) were independently associated with PVF. New-onset 3.03 (95% CI: 1.83-5.02), transient 2.40 (95% CI: 1.27-4.55), and permanent 2.99 (95% CI: 1.52-5.86) RBBB were independently associated with SVF.

CONCLUSION

New-onset RBBB and VF in STEMI are independently associated and show particularities based on the duration of the conduction disturbance and/or the primary or secondary character of the arrhythmia.

Acute myocardial infarction with right bundle branch block at presentation: Prevalence and mortality

AIMS

Right Bundle Branch Block (RBBB) has been reported in 5-11% of the acute myocardial infarctions (AMI), and it could be the only electrocardiographic abnormality in this group of patients. We investigated the mortality in patients with AMI and the presence of RBBB.

MATERIALS AND METHODS

A retrospective cohort study was conducted between January 2011 to December 2017 at a university hospital in Bogotá, Colombia. Records were obtained from all patients who presented at the emergency department with AMI; patients with early transfer and incomplete follow-up were excluded.

RESULTS

1015 patients were included, the mean age was 66 years, 67% of the patients were men, and 38% had STEMI. RBBB was documented in 8% of patients and LBBB in 4% of patients. In-hospital mortality was higher in the group of patients with RBBB vs. patients without RBBB (8.64% vs. 3.74%, p = 0.034). The percentage of patients with Killip ≥II classification was higher in patients with new RBBB vs. patients with old or unknown duration RBBB (23% vs. 13%, p = 0.216).

CONCLUSIONS

In patients with AMI, the presence of RBBB was associated with a statistically significant increase of in-hospital mortality.

In Hospital Outcomes of Patients With Right Bundle Branch Block and Anterior Wall ST-Segment Elevation Myocardial Infarction (From a Nationwide Study Using the National Inpatient Sample)

Previous studies have reported worse outcomes for patients with right bundle branch block (RBBB) complicating acute ST-segment elevation myocardial infarction (STEMI). There is a paucity of data examining outcomes with RBBB and STEMI in contemporary large-scale studies. This study aims to explore the outcomes of patients with anterior wall STEMI (AW-STEMI) and RBBB. Using ICD-9 codes, we queried the National Inpatient Sample of 1999 to 2014 to identify AW-STEMI admissions and stratified them for the presence of RBBB. Primary outcome was in-hospital mortality within 30 days. Secondary outcomes included acute heart failure, complete heart block, and permanent pacemaker implantation. Cox-proportional logistic regression models were used to determine the hazard ratios of the primary outcome and secondary outcomes and interventions. Among 1,075,875 weighted anterior wall STEMI (AW-STEMI) admissions, 19,153 (1.8%) had RBBB. Compared with patients without RBBB, mortality was significantly higher for patients with RBBB (9.2% vs 15.3%; p <0.0001). RBBB in the setting of AW-STEMI was associated with a 66% increased risk of 30-day in-hospital mortality (hazard ratios [HR], 1.66; 95% confidence interval [CI], 1.52 to1.81; p <0.0001) and a higher likelihood of acute heart failure (HR, 1.37; 95% CI, 1.29 to 1.45; p <0.0001), complete heart block (HR, 2.90; 95% CI, 2.64 to 3.18; p <0.0001) and utilization of a permanent pacemaker (HR, 2.51; 95% CI, 1.89 to 3.35; p <0.0001). In conclusion, the presence of RBBB in the setting of an AW-STEMI is a significant independent predictor of a poor prognosis, including a higher rate of acute heart failure, complete heart block, need for a permanent pacemaker, and a higher 30-day in-hospital mortality.

Differences in presentation and clinical outcomes between left or right bundle branch block and ST segment elevation in patients with acute myocardial infarction

Background:

In patients with acute myocardial infarction, the presence of a left bundle branch block or right bundle branch block may be associated with worse prognosis compared to isolated ST segment elevation. However, specificities in clinical presentation and outcomes of acute myocardial infarction patients with left bundle branch block or right bundle branch block are poorly characterized.

Methods:

We analysed acute myocardial infarction patients with left bundle branch block (n=880), right bundle branch block (n=732) or ST segment elevation without bundle branch block (n=15,852) included in the Acute Myocardial Infarction in Switzerland-Plus registry between 2008–2019.

Results:

Acute myocardial infarction patients with bundle branch block were older and had more pre-existing cardiovascular conditions compared to ST segment elevation. Pulmonary oedema and cardiogenic shock were most frequent in patients with left bundle branch block (18.8% vs 12.0% for right bundle branch block and 7.9% for ST segment elevation, p&lt;0.001). Acute myocardial infarction patients with bundle branch block had more three-vessel (40.6% vs 25.3%, p&lt;0.001 vs ST segment elevation) and left main disease (5.6% vs 2.0%, p&lt;0.001 vs ST segment elevation). Major adverse cardiac and cerebrovascular events, a composite of reinfarction, stroke/transient ischaemic attack, and death during hospitalization, were highest in acute myocardial infarction patients with left bundle branch block (13.9% vs 9.9% for right bundle branch block and 6.7% for ST segment elevation, p&lt;0.05), which was driven by hospital mortality. After multivariate adjustment, however, mortality was similar in patients with left bundle branch block and lower in patients with right bundle branch block, respectively, when compared to ST segment elevation. Mortality was only increased when a right bundle branch block with concomitant STE was present (odds ratio 1.77, 95% confidence interval 1.19–2.64, p&lt;0.01 vs ST segment elevation).

Conclusions:

Compared to ST segment elevation, an isolated bundle branch block reflects high-risk clinical characteristics but does not independently determine increased hospital mortality in acute myocardial infarction.

Prognostic impact of right bundle branch block in hospitalized patients with idiopathic dilated cardiomyopathy: a single-center cohort study

Objective

Idiopathic dilated cardiomyopathy (IDCM) is a primary myocardial disease resulting in symptoms of heart failure. Right bundle branch block (RBBB) is associated with increased cardiovascular risk and all-cause mortality. Therefore, the present study was performed to identify the prognostic impact of RBBB in patients with IDCM.

Methods

In total, 165 hospitalized patients with IDCM were evaluated. Receiver operating characteristic curve analysis was used to determine the cutoff point, and Cox regression was used to assess risk factors.

Results

After a median follow-up of 73.1 months (interquartile range, 36.1–88.7 months), 59 (35.8%) patients had died. All-cause mortality was significantly higher in patients with than without RBBB (log-rank χ2 = 9.400), P<0.05. Significant independent predictors of all-cause mortality in patients with IDCM were RBBB (hazard ratio, 2.898; 95% confidence interval, 1.201–6.995) and the left ventricular end-diastolic dimension (LVEDD) (hazard ratio, 1.034; 95% confidence interval, 1.004–1.066) at admission. Patients with RBBB and an LVEDD of ≥63 mm had the highest mortality (log-rank χ2 = 14.854), P<0.05.

Conclusion

RBBB was an independent predictor of all-cause mortality, and the combination of RBBB and LVEDD provided more clinically relevant information than RBBB alone for assessing the risk of all-cause mortality in patients with IDCM.

Prognostic value of new-onset right bundle-branch block in acute myocardial infarction patients: a systematic review and meta-analysis

BACKGROUND

Patients with acute myocardial infarction (AMI) and bundle-branch block have poor prognoses. The new European Society of Cardiology guideline suggests a primary percutaneous coronary intervention strategy when persistent ischemic symptoms occur in patients with persistent ischemic symptoms and right bundle-branch block (RBBB), but the level of evidence is not high. In fact, the presence of RBBB may lead to the misdiagnosis of transmural ischemia and mask the early diagnosis of ST-elevation myocardial infarction. Moreover, new-onset RBBB is occasionally caused by AMI. Our study aims to investigate the prognostic value of new-onset RBBB in AMI.

METHODS AND RESULTS

We conducted a meta-analysis of studies to evaluate the prognostic value of RBBB in AMI patients. Of 914 primary records, five studies and 874 MI patients were included for meta-analysis. Compared with previous RBBB, AMI patients with new-onset RBBB had a higher risk of long-term mortality (RR, 1.66, 95% CI [1.31-2.09], I2 = 0.0%, p = 0.000, n = 2), ventricular arrhythmia (RR, 4.86, 95% CI [2.10-11.27], I2 = 0.0%, p = 0.000, n = 3), and cardiogenic shock (RR, 2.76, 95% CI [1.66-4.59], I2 = 0.0%, p = 0.000, n = 3), but a lower risk of heart failure (RR, 0.66, 95% CI [0.52-0.85], I2 = 2.50%, p = 0.001, n = 4). Compared with AMI patients with new-onset permanent RBBB, patients with new-onset transient RBBB had a lower risk of short-term mortality (RR, 0.20, 95% CI [0.11-0.37], I2 = 44.1%, p = 0.000, n = 4).

CONCLUSION

New-onset RBBB is likely to increase long-term mortality, ventricular arrhythmia, and cardiogenic shock, but not heart failure in AMI patients. AMI patients with new-onset transient RBBB have a lower risk of short-term mortality than those with new-onset permanent RBBB. Revascularization therapies should be considered when persistent ischemic symptoms occur in patients with RBBB, especially new-onset RBBB.

Association between right ventricular systolic function and electromechanical delay in patients with right bundle branch block

BACKGROUND

Elevated right ventricle (RV) pressure and/or volume can place stress on the right bundle branch block (RBBB) and its associated Purkinje network, which can affect its electrical properties, resulting in conduction delay or block. We hypothesized that prolonged R' wave duration in lead V1 would extend the later portion of the QRS complex and can act as an indicator of reduced RV function in patients with RBBB.

METHOD

Kosin University Gospel Hospital echocardiography and electrocardiography (ECG) database was reviewed to identify patients with complete RBBB between 2013 and 2015. ECGs recorded closest to the time of the echocardiography were carefully reviewed, and QRS and R' wave duration were measured. RV systolic dysfunction was defined as an RV fractional area change (FAC) less than 35%, as indicated by echocardiography guidelines.

RESULTS

Compared to patients with normal RV function (n=241), patients with RV dysfunction (n=123) showed prolonged QRS duration (145.3±19.3ms vs. 132.2±13.4ms, p<0.001), predominantly due to R' prolongation (84.8±13.0ms vs. 102.9±12.0ms, p<0.001). R' duration was significantly associated with RV FAC (r=-0.609, p<0.001), RV systolic pressure (r=0.142, p=0.008), RV dimension (r=0.193, p<0.001), and RV myocardial performance index (r=0.199, p<0.001). On receiving operator characteristic curve analysis, V1 R' duration ≥93ms was associated with RV dysfunction with 90% sensitivity and 87% specificity (area under the curve: 0.883, 95% confidence interval=0.845-0.914, p<0.001).

CONCLUSION

Prolonged R' wave duration in lead V1 is an indicator of RV dysfunction and pressure and/or volume overload in patients with RBBB.

New or presumed new left bundle branch block in patients with suspected ST-elevation myocardial infarction

AIMS

Using a comprehensive large prospective regional ST-elevation myocardial infarction (STEMI) system database, we evaluated the prevalence, clinical and angiographic characteristics, and outcomes in patients with ischemic symptoms and new or presumed new left bundle branch block (LBBB). We then tested a new hierarchical diagnosis and triage algorithm to identify more accurately new LBBB patients with an acute culprit lesion.

METHODS AND RESULTS

From March 2003 to June 2013, 3903 consecutive STEMI patients were treated using the Minneapolis Heart Institute regional STEMI protocol including 131 patients (3.3%) with new LBBB. These patients had fewer culprit arteries (54.2% vs. 86.4%; P<0.001), were older, more commonly women, with a lower ejection fraction, and more frequently presented with cardiac arrest or heart failure than those without new LBBB. At 1 year follow-up, all-cause mortality accounting for baseline differences was higher in patients with new LBBB (hazard ratio 1.73, 95% confidence interval 1.17-2.58; P=0.007). The new algorithm yielded high sensitivity (97%) and negative predictive value (94%) for identification of a culprit lesion. Using the definition of new LBBB with either hemodynamically unstable features or Sgarbossa concordance criteria on electrocardiogram (ECG), 45% of new LBBB patients would have been treated as 'STEMI equivalent'.

CONCLUSION

Patients with acute ischemic symptoms and new LBBB represent a high-risk population with unique clinical challenges. If validated in an independent dataset, the new algorithm may improve the diagnostic accuracy regarding reperfusion therapy for new LBBB patients.

Left ventricular ejection fraction and mortality in patients with ST-elevation myocardial infarction and bundle branch block

BACKGROUND

The aim of our study is to assess the effect of bundle branch block (BBB) on mortality and left ventricular ejection fraction (LVEF) in ST-elevation myocardial infarction (STEMI) patients treated in the current era of percutaneous reperfusion therapy.

PATIENTS AND METHODS

In this retrospective cohort study, a total of 1123 STEMI patients treated in the University Medical Center Groningen from January 2011 until May 2013 were included. The follow-up duration was 2-4 years. Transthoracic echocardiography was performed within 2 weeks after STEMI.

RESULTS

In total, 23 (2.0%) patients presented with left BBB and 49 (4.4%) patients presented with right BBB. Two-year mortality after STEMI was 25.0% (n=18) in patients with BBB and 9.2% (n=97, P<0.001) in patients without BBB. Patients with BBB had more frequently a severely reduced LVEF (<30%) [20.0% (n=6) compared with 4.2% (n=21), P=0.002] and less frequently a normal LVEF [16.7% (n=5) compared with 35.7% (n=179), P=0.046]. After multivariable analysis, BBB did not remain an independent predictor of mortality, but was an independent predictor of reduced LVEF.

CONCLUSION

The presence of a BBB was an independent predictor of a reduced LVEF. However, we found no effect of BBB on 2-year mortality in the current era of percutaneous reperfusion therapy.

Prognostic Significance of Right Bundle Branch Block for Patients with Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Background

The aim of the current meta-analysis was to assess the effect of right bundle branch block (RBBB) on mortality outcome in patients with acute myocardial infarction (AMI).

Material/Methods

Embase, PubMed, and Cochrane databases were searched through January 2015 using the keywords “RBBB”, “mortality”, “AMI”, “Coronary Heart Disease”, and “cardiovascular”. An odds ratio (OR) of RBBB on mortality endpoints was calculated using random-effects models.

Results

RBBB was associated with significantly increased overall mortality in patients with AMI. The OR of RBBB for deaths was 1.56 [95% confidence interval (CI), 1.44 to 1.68, p<0.001]. Moreover, RBBB showed a considerable effect on both in-hospital mortality (OR: 1.94, 95% CI: 1.60 to 2.37, p=0.002) and long-term mortality (OR: 1.49, 95% CI: 1.37 to 1.62, p<0.001).

Conclusions

RBBB is associated with an increased risk of all-cause mortality and indicates a poorer prognosis in patients with AMI.

Clinical Characteristics, Management, and Outcomes of Acute Coronary Syndrome in Patients With Right Bundle Branch Block on Presentation

We examined the relations between right bundle branch block (RBBB) and clinical characteristics, management, and outcomes among a broad spectrum of patients with acute coronary syndrome (ACS). Admission electrocardiograms of patients enrolled in the Global Registry of Acute Coronary Events (GRACE) electrocardiogram substudy and the Canadian ACS Registry I were analyzed independently at a blinded core laboratory. We performed multivariable logistic regression analysis to assess the independent prognostic significance of admission RBBB on in-hospital and 6-month mortality. Of 11,830 eligible patients with ACS (mean age 65; 66% non-ST-elevation ACS), 5% had RBBB. RBBB on admission was associated with older age, male sex, more cardiovascular risk factors, worse Killip class, and higher GRACE risk score (all p <0.01). Patients with RBBB less frequently received in-hospital cardiac catheterization, coronary revascularization, or reperfusion therapy (all p <0.05). The RBBB group had higher unadjusted in-hospital (8.8% vs 3.8%, p <0.001) and 6-month mortality rates (15.1% vs 7.6%, p <0.001). After adjusting for established prognostic factors in the GRACE risk score, RBBB was a significant independent predictor of in-hospital death (odds ratio 1.45, 95% CI 1.02 to 2.07, p = 0.039), but not cumulative 6-month mortality (odds ratio 1.29, 95% CI 0.95 to 1.74, p = 0.098). There was no significant interaction between RBBB and the type of ACS for either in-hospital or 6-month mortality (both p >0.50). In conclusion, across a spectrum of ACS, RBBB was associated with preexisting cardiovascular disease, high-risk clinical features, fewer cardiac interventions, and worse unadjusted outcomes. After adjusting for components of the GRACE risk score, RBBB was a significant independent predictor of early mortality.

Relation of New Permanent Right or Left Bundle Branch Block on Short- and Long-Term Mortality in Acute Myocardial Infarction Bundle Branch Block and Myocardial Infarction

The aim of this study was to investigate the prognosis associated with bundle branch block (BBB) depending on location, time of appearance, and duration in patients with myocardial infarction (MI). From January 1998 to January 2008, we recruited 5,570 patients with acute MI. Thirty-day and 7-year all-cause mortality, according to BBB location, time of appearance, and duration were analyzed by multivariable analyses. BBB was present in 964 patients (17.3%); right BBB (RBBB) 10.6% and left BBB (LBBB) 6.7%. Overall mortality rate at 30 days was 13.2% (n = 738) and 7 years was 6.34 deaths per 100 patient-year. Both RBBB and LBBB were more frequently previous, 42.9% and 58.8%. Compared with non-BBB, all BBB groups showed higher prevalence of co-morbidities, especially rates of diabetes (49.0% vs 34.3%, p <0.001) and more often heart failure during hospitalization (54.5% vs 26.6%, p <0.001). Compared with RBBB, patients with LBBB had a higher prevalence of co-morbidities and a higher mortality, especially the new BBB, 30 days: 52.5% versus 31.6% and 7 years (incident rate): 27.2 versus 13.3 per 100 patient-year. New transient BBB had lower heart failure on admission (42.6% vs 58.3%, p = 0.008) and 30-day mortality (20.3% vs 69.6%, p <0.001) compared with permanent in both locations. New permanent RBBB was independently associated with 30-day (hazard ratio [HR] 2.01, 95% confidence interval [CI] 1.45 to 2.79) and 7-year mortality (HR 3.12, 95% CI 2.38 to 4.09). New-permanent LBBB was independently associated with 30-day (HR 2.15, 95% CI 1.47 to 3.15) and 7-year mortality (HR 2.91, 95% CI 2.08 to 4.08). In conclusion, in patients with acute MI, the appearance of a new BBB was independently associated with a higher 30-day and 7-year all-cause mortality.

Significance of an isolated new right bundle branch block in a patient with chest pain

Chest pain is a common presenting symptom in emergency departments, and a typical manifestation of acute myocardial infarction (AMI). Recognition of ECG changes in AMI is essential for timely diagnosis and treatment. Right bundle branch block (RBBB) may be an isolated sign of AMI, and was previously considered as a criterion for fibrinolytic therapy. Since the most recent European Society of Cardiology and American Heart Association guidelines in 2013, RBBB alone is no longer considered a diagnostic criterion of AMI, even if it occurs in the context of acute chest pain, as RBBB does not usually interfere with the interpretation of ST-segment alteration. Our case illustrates an acute septal myocardial infarction with an isolated RBBB, and thus the importance of recognising this pattern in order to permit timely diagnosis and treatment.

ST-segment elevation myocardial infarction in women with type 2 diabetes

OBJECTIVE

To evaluate the effect of type 2 diabetes on the clinical course and prognosis of women with ST-segment elevation myocardial infarction (STEMI) and diabetes.

RESEARCH DESIGN AND METHODS

A total of 26,035 consecutive patients with STEMI who were hospitalized in 456 hospitals in Poland during 1 year were analyzed. The data were obtained from the Polish Registry of Acute Coronary Syndromes (PL-ACS).

RESULTS

Type 2 diabetes occurred more frequently in women than in men (28 vs. 16.6%; P < 0.0001). The proportion of women was larger among patients with diabetes (47.1 vs. 31.3%; P < 0.0001), and compared with women without diabetes, diabetic women had worse clinical profiles. Women with diabetes were most frequently treated conservatively. Both women and men with diabetes had significantly more advanced atherosclerotic lesions than women without diabetes. Women with diabetes had the highest in-hospital, 6-month, and 1-year mortality rates. Multivariate analysis indicated that type 2 diabetes was a significant independent risk factor for in-hospital and 1-year mortality in women with STEMI. Primary percutaneous coronary intervention (pPCI) was a significant factor associated with the decreased 1-year mortality in women without diabetes.

CONCLUSIONS

Type 2 diabetes was a significant independent risk factor for in-hospital and 1-year mortality in women with STEMI. Women with diabetes had the poorest early and 1-year prognoses after STEMI when compared with women without diabetes and men with diabetes. Although pPCI improves the long-term prognosis of women with diabetes, it is used less frequently than in women without diabetes or men with diabetes.

[Coronary revascularization during cardiopulmonary resuscitation. The bridge code]

Cardiac arrest is one of the major current challenges, due to both its high incidence and mortality and the fact that it leads to severe brain dysfunction in over half of the survivors. The so-called coronary origin Bridge Code is presented, based on the international resuscitation recommendations (2005, 2010). In accordance with a series of strict predictive criteria, this code makes it possible to: (1) select refractory CPR patients with a high or very high presumption of underlying coronary cause; (2) evacuate the patient using mechanical chest compressors [LucasTM, Autopulse®], maintaining coronary and brain perfusion pressures; (3) allow coronary revascularization access during resuscitation maneuvering (PTCA during ongoing CPR); (4) induce early hypothermia; and (5) facilitate post-cardiac arrest intensive care. In the case of treatment failure, the quality of hemodynamic support makes it possible to establish a second bridge to non-heart beating organ donation.