Routine Right Heart Catheterization Research Articles

PORTOPULMONARY HYPERTENSION PRACTICE PATTERNS AFTER LIVER TRANSPLANTATION

PORTOPULMONARY HYPERTENSION PRACTICE PATTERNS AFTER LIVER TRANSPLANTATION

The Role of Serial Right Heart Catheterization Survey in Patients Awaiting Heart Transplant on Ventricular Assist Device.

Current guidelines recommend serial right heart catheterization (RHC) to survey pulmonary hypertension in patients awaiting heart transplant. However, the role and impact of this surveillance is unclear in patients with a left ventricular assist device (LVAD). We reviewed our surveillance RHC protocol to determine whether useful data were obtained to justify the risks of serial invasive procedures (i.e., excessive bleeding). Between January 2015 and December 2018, 78 patients who received an LVAD as bridge-to-transplant (BTT) were included in this study. Routine RHC surveillance was performed every 6 months. Hemodynamic variables were retrospectively collected and reviewed. In 78 patients, 205 RHCs were analyzed. Median patient age was 54 years (IQR 46-61), and 64 (82%) were male. Thirty-six patients (46%) had pulmonary vascular resistance (PVR) ≤ 3 Wood units (WUs), and 42 patients (54%) had PVR > 3 WUs before LVAD. After LVAD implantation, mean PVR decreased by 36% from 3.8 ± 2.1 to 2.4 ± 1.1 WUs (p < 0.001) at 6 months and stabilized below 3 WUs at all post-LVAD time points. Four patients (11%) with pre-LVAD PVR ≤ 3 and 16 patients (38%) with a pre-LVAD PVR > 3 had PVR > 3 at least once during RHC survey. Of the 56 (76%) transplanted patients, six (40%) of 15 patients with a post-LVAD PVR >3 at least once developed moderate-to-severe right ventricular dysfunction. Although PVR significantly decreased after LVAD implant, PVR values fluctuated, particularly for those with pre-LVAD PVR > 3.0 WUs. Routine RHC appears valid for all BTT patients.

MR 4D flow-based mean pulmonary arterial pressure tracking in pulmonary hypertension

ObjectivesLongitudinal hemodynamic follow-up is important in the management of pulmonary hypertension (PH). This study aimed to evaluate the potential of MR 4-dimensional (4D) flow imaging to predict changes in the mean pulmonary arterial pressure (mPAP) during serial investigations.MethodsForty-four adult patients with PH or at risk of developing PH repeatedly underwent routine right heart catheterization (RHC) and near-term MR 4D flow imaging of the main pulmonary artery. The duration of vortical blood flow along the main pulmonary artery was evaluated from MR 4D velocity fields using prototype software and converted to an MR 4D flow imaging-based mPAP estimate (mPAPMR) by a previously established model. The relationship of differences between RHC-derived baseline and follow-up mPAP values (ΔmPAP) to corresponding differences in mPAPMR (ΔmPAPMR) was analyzed by means of regression and Bland-Altman analysis; the diagnostic performance of ΔmPAPMR in predicting mPAP increases or decreases was investigated by ROC analysis.ResultsAreas under the curve for the prediction of mPAP increases and decreases were 0.92 and 0.93, respectively. With the natural cutoff ΔmPAPMR = 0 mmHg, mPAP increases (decreases) were predicted with an accuracy, sensitivity, and specificity of 91% (91%), 85% (89%), and 94% (92%), respectively. For patients in whom 4D flow allowed a point estimate of mPAP (mPAP > 16 mmHg), ΔmPAPMR correlated strongly with ΔmPAP (r = 0.91) and estimated ΔmPAP bias-free with a standard deviation of 5.1 mmHg.ConclusionsMR 4D flow imaging allows accurate non-invasive prediction and quantification of mPAP changes in adult patients with PH or at risk of developing PH.Trial registrationClinicalTrials.gov identifier: NCT00575692 and NCT01725763Key Points• MR 4D flow imaging allows accurate non-invasive prediction of mean pulmonary arterial pressure increases and decreases in adult patients with or at risk of developing pulmonary hypertension.• In adult patients with mean pulmonary arterial pressure > 16 mmHg, MR 4D flow imaging allows estimation of longitudinal mean pulmonary arterial pressure changes without bias with a standard deviation of 5.1 mmHg.

High Right Ventricular Afterload is Associated with Impaired Exercise Tolerance in LVAD Patients

Purpose Exercise tolerance, measured by pVO 2 during cardiopulmonary exercise stress test (CPET), is impaired in patients with LVAD. After LVAD, the right heart is more sensitive to afterload. We hypothesize that high RV afterload during exercise is associated with lower pVO 2 . Methods At routine right heart catheterization (RHC), LVAD patients performed supine bicycle exercise to maximal effort. Hemodynamics and echocardiograms at rest and peak exercise were collected. The same patients underwent CPET on different days as part of routine post-operative monitoring. We used effective arterial elastance (Ea = systolic PAP/stroke volume) to measure RV afterload, as it incorporates both pulsatile and resistive loads. Results Between 11/17 and 9/18, 10 patients (median age 54 years) had RHC, 8 of them had CPET. Time between LVAD and RHC was 244 days (IQ 223-299) and between CPET and RHC was 55 days (IQ 35-126). Work achieved (Watts) during CPET and RHC correlated linearly (α=1.1, p=0.003, R²=0.60). Patients had low pVO 2 (13.2 L/kg/min, IQ 11-18) and high VEVCO 2 slope (34, IQ 32-43) despite normal filling pressures and cardiac output (CO) after LVAD. They had no chronotropic incompetence (reaching 89.5% of max predicted heart rate, IQ 66.4-95.4). Compared to resting state, at peak exercise, filling pressures, CO, RV stroke work index, and RV tissue Doppler (S’) increased. Notably, pVO 2 negatively correlated with Ea at peak exercise and the change in Ea from rest to stress, while VEVCO 2 slope had the inverse correlations (Figure). pVO 2 did not correlate with changes in PCWP, CO, or LVAD flow. Moderate-severe baseline RV dysfunction and mild-moderate TR are associated with worse pVO 2 and VEVCO 2 slope. Conclusion This pilot study is the first to suggest that poor baseline RV function and high RV afterload at peak exercise are associated with worse pVO 2 and VEVCO 2 slope in LVAD patients. The practice of increasing pump speed may not be adequate to improve exercise tolerance and may be harmful to RV function.

Poor Left Ventricular Unloading is Associated with Increased Mortality after Continuous Flow Left Ventricular Assist Device Implantation

Purpose The role of routine right heart catheterization (RHC) to evaluate for left ventricular (LV) unloading remains unclear in patients with continuous flow left ventricular assist devices (CF-LVAD). We hypothesized that persistently elevated pulmonary capillary wedge pressure (PCWP) would be associated with increased mortality on CF-LVAD support. Methods A single center continuous flow LVAD cohort (n=451) was queried for patients with follow-up RHC data at 6 months +/- 3 months (n=179). To determine the relationship between follow-up PCWP and mortality, a multivariable cox regression analysis was performed. Results The mean age of the study cohort was 57±13 years. 79% (141/179) were males, 56% (101/179) had ischemic cardiomyopathy and 74% (133/179) were designated bridge to transplant (BTT). The median follow-up time on LVAD support after RHC was 4.4 years. The only pre-implant variables that were associated with elevated PCWP in the multivariate analysis were renal function and BMI (each 2.5 unit increase in BMI was associated with an adjusted 0.6 mmHg increase in follow-up PCWP, 95% CI 0.2-0.9 mmHg, p=0.004; each 0.5 mg/dL increase in creatinine was associated with a 1.2 mmHg increase in follow-up PCWP, 95% CI 0.4-2.1, p=0.003). In the final multivariate models, each 5 mmHg increase in PCWP at the time of RHC was associated with a 22% increase in the hazards rate of death during follow-up (adjusted HR 1.2, 95% CI 1.01-1.47, p=0.039). All models were adjusted for age, sex, INTERMACS profile, body mass index, bridge to transplant status and renal function. Conclusion Incomplete LV unloading following CF-LVAD implantation is associated with increased all-cause mortality. Our results emphasize the importance of invasive hemodynamic optimization in this patient population. Further studies are warranted to determine the optimal filling pressures in patients with CF-LVAD.

Routine Right Heart Catheterization in LVAD Patients Awaiting Heart Transplant: What is the Appropriate Surveillance Interval?

Purpose ISHLT guidelines recommend serial right heart catheterization (RHC) to survey pulmonary hypertension in patients awaiting heart transplant. In LVAD as BTT patients the ideal surveillance frequency is unknown in those without prior pulmonary hypertension or whose pre-LVAD PVR normalized after surgery. Here, we review the utility of our surveillance RHC protocol. Methods Between January 2017 and July 2018, 69 patients who received an LVAD as BTT were studied. Routine RHC was performed every six months irrespective of prior PVR. Hemodynamic variables were retrospectively collected and reviewed. Results In 69 patients, 217 RHCs were analyzed. The median age was 55 years (IQR=15), and 55 (80%) were male. Median follow-up period was 18.4 months, and hemodynamic variables were largely unchanged post-LVAD (Table). Post-LVAD, overall PVR decreased from 3.5 ± 2.1 to 2.4 ± 1.0 Wood units (p = 7.2e-5) at six months and stabilized below 3 at all time points. Thirty-three patients (48%) had PVR ≤ 3 (1.8 ± 0.7), and 36 patients (52%) had PVR > 3 (4.9 ± 2.0) pre-LVAD. Both groups exhibited stabilization of PVR with mean 3 at any point after LVAD implantation, 13 (81%) had a pre-LVAD PVR > 3. No patients with a PVR ≤ 3 six months post-LVAD implantation presented with a PVR > 3 at any subsequent RHC. Of the 40 patients (58%) transplanted, one patient developed severe primary graft dysfunction with right ventricular failure. Conclusion Routine RHC every six months may not be necessary for BTT patients, particularly for those with PVR ≤ 3 six months post LVAD.

Echocardiographic Predictors of Hemodynamics in Patients Supported With Left Ventricular Assist Devices

The assessment of hemodynamics in patients supported with left ventricular assist devices (LVADs) is often challenging. Physical examination maneuvers correlate poorly with true hemodynamics. We assessed the value of novel transthoracic echocardiography (TTE)-derived variables to reliably predict hemodynamics in patients supported with LVAD. A total of 102 Doppler-TTE images of the LVAD outflow cannula were obtained during simultaneous invasive right heart catheterization (RHC) in 30 patients supported with continuous-flow LVADs (22 HMII, 8 HVAD) either during routine RHC or during invasive ramp testing. Properties of the Doppler signal though the outflow cannula were measured at each ramp stage (RS), including the systolic slope (SS), diastolic slope (DS), and velocity time integral (VTI). Hemodynamic variables were concurrently recorded, including Doppler opening pressure (MAP), heart rate (HR), right atrial pressure, pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP), Fick cardiac output (CO) and systemic vascular resistance (SVR). Univariate and multivariate regression analyses were used to explore the dependence of PCWP, CO, and SVR on DS, SS, VTI, MAP, HR, and RS. Multivariate linear regression analysis revealed significant contributions of DS on PCWP (PCWPpred = 0.164DS + 4.959; R = 0.68). Receiver operating characteristic (ROC) curve analysis revealed that PCWPpred could predict an elevated PCWP ≥18 mm Hg with a sensitivity (Sn) of 94% and specificity (Sp) of 85% (area under the ROC curve 0.88). CO could be predicted by RS, VTI, and HR (COpred = 0.017VTI + 0.016HR + 0.12RS + 2.042; R = 0.61). COpred could predict CO ≤4.5 L/min with Sn 73% and Sp 79% (AUC 0.81). SVR could be predicted by MAP, VTI, and HR (SVRpred = 15.44MAP - 5.453VTI - 6.349HR + 856.15; R = 0.84) with Sn 84% and Sp 79% (AUC 0.91) to predict SVR ≥1200 dyn-s/cm5. Doppler-TTE variables derived from the LVAD outflow cannula can reliably predict PCWP, CO, and SVR in patients supported with LVADs and may mitigate the need for invasive testing.

Prognostic Effect and Longitudinal Hemodynamic Assessment of Borderline Pulmonary Hypertension

Pulmonary hypertension (PH) is diagnosed by a mean pulmonary arterial pressure (mPAP) value of at least 25 mm Hg during right heart catheterization (RHC). While several studies have demonstrated increased mortality in patients with mPAP less than that threshold, little is known about the natural history of borderline PH. To test the hypothesis that patients with borderline PH have decreased survival compared with patients with lower mPAP and frequently develop overt PH and to identify clinical correlates of borderline PH. Retrospective cohort study from 1998 to 2014 at Vanderbilt University Medical Center, comprising all patients undergoing routine RHC for clinical indication. We extracted demographics, clinical data, invasive hemodynamics, echocardiography, and vital status for all patients. Patients with mPAP values of 18 mm Hg or less, 19 to 24 mm Hg, and at least 25 mm Hg were classified as reference, borderline PH, and PH, respectively. Mean pulmonary arterial pressure. Our primary outcome was all-cause mortality after adjusting for clinically relevant covariates in a Cox proportional hazards model. Our secondary outcome was the diagnosis of overt PH in patients initially diagnosed with borderline PH. Both outcomes were determined prior to data analysis. We identified 4343 patients (mean [SD] age, 59 [15] years, 51% women, and 86% white) among whom the prevalence of PH and borderline PH was 62% and 18%, respectively. Advanced age, features of the metabolic syndrome, and chronic heart and lung disease were independently associated with a higher likelihood of borderline PH compared with reference patients in a logistic regression model. After adjusting for 34 covariates in a Cox proportional hazards model, borderline PH was associated with increased mortality compared with reference patients (hazard ratio, 1.31; 95% CI, 1.04-1.65; P = .001). The hazard of death increased incrementally with higher mPAP, without an observed threshold. In the 70 patients with borderline PH who underwent a repeated RHC, 43 (61%) had developed overt PH, with a median increase in mPAP of 5 mm Hg (interquartile range, -1 to 11 mm Hg; P < .001). Borderline PH is common in patients undergoing RHC and is associated with significant comorbidities, progression to overt PH, and decreased survival. Small increases in mPAP, even at values currently considered normal, are independently associated with increased mortality. Prospective studies are warranted to determine whether early intervention or closer monitoring improves clinical outcomes in these patients.

Utility of Routine Right Heart Catheterization after LVAD Implantation

Purpose Continuous flow left ventricular assist devices (LVADs) have a positive effect on pulmonary hypertension (PH) that is critical for patients implanted as bridge to heart transplant (BTT). Routine right heart catheterization (RHC) for evaluation of PH is frequently done after LVAD implant. We describe the role of RHC in treatment of PH in patients with an LVAD as BTT. Methods and Materials We performed a retrospective analysis of treatment of PH based on results of RHC in patients with isolated LVAD for more than 6 months. Thirty eight patients implanted with LVAD as BTT from 2008-2012 were included. Of those, 24 patients (63%) had a pulmonary vascular resistance (PVR) >2.5 at time of implant (Group A), and 14 patients (37%) had PVR Results Average duration of support was 20.5±9.1 and 21.5±10.6 months for Group A and B, respectively (NS). Mean PVR for Group A and B are presented in table 1 . Five patients in group A required treatment of PH, by addition or up-titration of PDE-5 inhibitor, as a result of routine RHC, compared to none in Group B. There were no major complications with RHC. Conclusions There was no need for treatment of PH in patients with normal PVR at LVAD implant. None of the patients with PVR PVR > 2.5 PVR p Pre-implant 4.2±1.25 1.7±0.81 6 months 2.1±0.97 1.8±0.57 0.35 12 months 1.9±0.82 1.9±0.64 0.93 18 months 1.8±0.83 1.6±0.32 0.60

Bronchial carcinoma and pulmonary hypertension. Significance for lung resection

In 227 patients with bronchial carcinoma whose forced expiratory volume was less than 2.5 l, measurements revealed a mild but significant rise in mean pulmonary arterial pressure at rest and on mild exercise (60 W). There was no clinically useful correlation between the degree of pulmonary hypertension and other measurable values, such as stage of the tumor or spirometric, whole-body plethysmographic, scintigraphic, electrocardiographic and blood-gas measurements. The degree of pre-operative pulmonary hypertension in 142 operated patients correlated with neither postoperative complications nor with post-operative mortality. Six months after lung resection there was a mild rise in pulmonary artery mean pressure among 30 patients, statistically significant only in those after pneumonectomy at rest. These results do not justify routine pre-operative right-heart catheterization. This should be reserved for patients with marginal ventilatory findings and cardiac risk factor.

901-84 Prognostic Value of Right Heart Catheterization Hemodynamic Data in Surgically Treated Patients with Coronary Artery Disease

Routine right heart catheterization (RHC) provides limited prognostic information in medically treated patients with coronary artery disease. The use of this procedure in patients undergoing coronary artery bypass grafting has been more widely advocated. To determine the value of this practice, we investigated the added prognostic content of hemodynamic data obtained from 11 RHC variables in 1054 consecutive surgically treated patients (pts) with significant coronary artery disease ( ≥ 75% stenosis) between 8/6/69 and 1/1/80. During this period, RHC was performed routinely on all patients undergoing left heart catheterization (LHC). Follow up was 97% complete. Univariate RHC predictors of survival included pulmonary vascular resistance (PVR). right atrial mean (RAM). CO, CI, AVO 2 difference, RV systolic pressure, PA systolic, mean and diastolic pressures, and pulmonary capillary wedge pressure (p &lt; 0.0001 for each). Age yrs (median) 52 (20-78) Male 83% EF (median) 53% (5-60) Hx of CHF 10.1% Prior MI 46.3% LVEDP (median) 11 mmHg Using a Cox model the independent predictive value of each RHC variable was analyzed when added to a prognostic model derived from clinical and LHC data. RAM (x 2 = 18.5, P &lt; 0.001) and PVR (x 2 = 8.45, P &lt; 0.001) added independent information to the standard clinical and invasive (left heart) prognostic factors. A significant interaction was found between PVR and EF (p = 0.0067) indicating that elevated PVR contained more prognostic information in patients with normal or elevated EF.

Right-heart catheterization in coronary artery disease.

The performance of routine right-heart catheterization on patients under going study for coronary artery disease is a subject of controversy. Accordingly, data from 100 consecutive patients who had coronary arteriography and right- heart catheterization were analyzed. Seventy-nine had significant (&gt;70% ste nosis) coronary disease (group I), and 21 had patent coronary vessels (group II). Although group I patients had a lower ejection fraction (EF) 53 ± 2 vs 65 ± 2%, P &lt; 0.05) and stroke work index (SW) (52 ± 2.2 vs 69 ±4.2 Gm-m/m2, P &lt; 0.001) than group II patients, systolic pulmonary artery (PA) pressure (31 ± 1.6 vs 26 ± 1.2 mmHg, NS), pulmonary arteriolar resistance (PAR) (2.3 ± 0.2 vs 1.7 ± 0.2 u,NS), and cardiac index (CI) (3.1 ± 0.3 vs 3.1 ± 0.2 L/min/m2, NS) were not different. Systolic PA pressure in group I correlated with left ventricular end-diastolic pressure (LVEDP), SW, and EF, but these relationships were not strong (r &lt; 0.57, all P &lt; 0.01). Eight patients had a PA pressure greater than 50 mm Hg (66 ± 3.8 mm Hg). All had multivessel disease, extensive asynergy, significant mitral regurgitation, and severe left ventricular dysfunction (CI: 2.2 ± 0.3 L/ min/m2; LVEDP: 33 ± 2 mm Hg; SW: 28 ± 5.5 gm-m/m2 ; EF: 25 + 2%); all were considered inoperable. Six other group I patients also had an EF less than 30% but had lower systolic PA pressures. Four of these had hemodynamic findings indistinguishable from those with severe PA hypertension, whereas 2 had localized aneurysms and no mitral regurgitation, and both survived an open-heart operation. Thus this study supports the view that routine right-heart catheterization in coronary artery disease does not provide additional information that might help in determining patient prognosis or suitability for coronary by-pass surgery.