Right ventricular function at rest and during exercise in aortic and mitral valve disease

The association of Pulmonary Hypertension and right ventricular systolic function - updates in diagnosis and treatment

Right ventricular (RV) systolic function is an essential but neglected component in cardiac evaluation, and its importance to the contribution to overall cardiac function is undermined. It is not only sensitive to the effect of left heart valve disease but is also more sensitive to changes in pressure overload than the left ventricle. Pulmonary Hypertension is the common and well-recognized complication of RV systolic dysfunction. It is also the leading cause of pulmonary valve disease and right ventricular dysfunction. Patients with a high pulmonary artery pressure (PAP) and a low RV ejection fraction have a seven-fold higher risk of death than heart failure patients with a normal PAP and RV ejection fraction. Furthermore, it is an independent predictor of survival in these patients. In this review, we examine the association of right ventricular systolic function with Pulmonary Hypertension by focusing on various pathological and clinical manifestations while assessing their impact. We also explore new 2022 ESC/ERS guidelines for diagnosing and treating right ventricular dysfunction in Pulmonary Hypertension.

Right Ventricular Dysfunction and Short-Term Outcomes Following Left-Sided Valvular Surgery: An Echocardiographic Study

Background The prognostic value of echocardiographic evaluation of right ventricular (RV) function in patients undergoing left-sided valvular surgery has not been well described. The objective of this study is to determine the role of broad echocardiographic assessment of RV function in predicting short-term outcomes after valvular surgery. Methods and Results Preoperative echocardiographic data, perioperative adverse outcomes, and 30-day mortality were analyzed in patients who underwent left-sided valvular surgery from 2006 to 2014. Echocardiographic parameters used to evaluate RV function include RV fractional area change, tricuspid annular plane systolic excursion, systolic movement of the RV lateral wall using tissue Doppler imaging (S'), RV myocardial performance index, and RV dP/dt. Subjects with at least 3 abnormal parameters out of the 5 aforementioned indices were defined as having significant RV dysfunction. The study included 269 patients with valvular surgery (average age: 67±15, 60.6% male, 148 aortic, and 121 mitral). RV dysfunction was found in 53 (19.7%) patients; 30-day mortality occurred in 20 patients (7.5%). Compared with normal RV function, patients with RV dysfunction had higher 30-day mortality (22.6% versus 3.8%; P=0.01) and were at risk for developing multisystem failure/shock (13.2% versus 3.2%; P=0.01). Multivariate analyses showed that preexisting RV dysfunction was the strongest predictor of increased 30-day mortality (odds ratio: 3.5; 95% CI, 1.1-11.1; P<0.05). Conclusions Preoperative RV dysfunction identified by comprehensive echocardiographic assessment is a strong predictor of adverse outcomes following left-sided valvular surgery.

Impact of net atrioventricular compliance on clinical outcome in mitral stenosis

BACKGROUND

Net atrioventricular compliance (Cn) has been reported to be an important determinant of pulmonary hypertension in mitral stenosis (MS). We hypothesized that it may be useful in assessing prognosis because Cn reflects hemodynamic consequences of MS. To date, limited data with an assumed Cn cutoff have indicated the need for larger prospective studies. This prospective study was designed to determine the impact of Cn on clinical outcome and its contribution to pulmonary pressure in MS. In addition, we aimed to identify a cutoff value of Cn for outcome prediction in this setting.

METHODS AND RESULTS

A total of 128 patients with rheumatic MS without other significant valve disease were prospectively enrolled. Comprehensive echocardiography was performed and Doppler-derived Cn estimated using a previously validated equation. The end point was either mitral valve intervention or death. Cn was an important predictor of pulmonary pressure, regardless of classic measures of MS severity. During a median follow-up of 22 months, the end point was reached in 45 patients (35%). Baseline Cn predicted outcome, adding prognostic information beyond that provided by mitral valve area and functional status. Cn ≤4 mL/mm Hg best predicted unfavorable outcome in derivation and validation sets. A subgroup analysis including only initially asymptomatic patients with moderate to severe MS without initial indication for intervention (40.6% of total) demonstrated that baseline Cn predicted subsequent adverse outcome even after adjustment for classic measures of hemodynamic MS severity (hazard ratio, 0.33; 95% confidence interval, 0.14-0.79; P=0.013).

CONCLUSIONS

Cn contributes to pulmonary hypertension beyond stenosis severity itself. In a wide spectrum of MS severity, Cn is a powerful predictor of adverse outcome, adding prognostic value to clinical data and mitral valve area. Importantly, baseline Cn predicts a progressive course with subsequent need for intervention in initially asymptomatic patients. Cn assessment therefore has potential value for clinical risk stratification and monitoring in MS patients.

The impact of right ventricular stroke work on B-type natriuretic peptide levels in patients with mitral stenosis undergoing percutaneous mitral valvuloplasty

OBJECTIVES

We aimed to explore the relationship between brain natriuretic peptide (BNP) levels and right ventricular (RV) function in patients with mitral stenosis (MS), and to investigate the hemodynamic parameters that predict reduction of BNP levels after percutaneous mitral valvuloplasty (PMV).

BACKGROUND

Few studies have evaluated BNP in the context of MS, specifically the impact of the RV stroke work (RVSW) on serum BNP levels has not been defined.

METHODS

Thirty patients with symptomatic rheumatic MS in sinus rhythm who were referred for a PMV were enrolled. Right and left heart pressures were obtained before and after valvuloplasty. RVSW index (RVSWI) was calculated by cardiac catheterization.

RESULTS

Basal BNP levels were elevated in MS patients and correlated with several hemodynamic parameters including pulmonary pressure, pulmonary vascular resistance index, cardiac index (CI), and RVSWI. In multivariate analysis, CI and RVSWI were independent predictors of raised basal BNP levels. PMV resulted in a significant decrease in the RVSWI with a concurrent increase in CI (2.4 ± 0.43 to 2.9 ± 0.8 L/min/m(2), P = 0.010). Overall, plasma BNP levels significantly decreased from 124 (63/234) to 73 (48/148) pg/ml postvalvuloplasty. Multivariate analysis revealed that the reduction of left atrial (LA) pressure post-PMV was an independent predictor of change in BNP levels.

CONCLUSIONS

Elevated baseline BNP level in MS patients was independently associated with CI and RVSWI. Plasma BNP levels were reduced after successful PMV, which was associated with the reduction of the LA pressure.

The Role of Right Ventricular Function in Mitral Valve Surgery

<p><b>Background:</b> An impaired right ventricular function is associated with a poor survival rate in patients with heart failure. Few investigations have analyzed the prognostic value of right ventricular function on the outcomes of mitral valve (MV) surgery. The objectives of this study were to define the effect of right ventricular function on postoperative outcomes after MV repair (MVP) or replacement (MVR).</p><p><b>Methods:</b> From September 2007 to February 2012, 335 consecutive patients underwent MVP or MVR at our institution. Preoperative transthoracic and transesophageal echocardiography (TEE) and postoperative TEE were used to define right ventricular function and MV performance. Preoperative right ventricular function was graded as normal to mild (grade 1-2) or as moderate to severe (grade 3-4). MV or tricuspid valve regurgitation was graded as non-trivial to mild (grade 0-2) or as moderate to severe (grade 3-4) preoperatively and postoperatively. Survival rate was evaluated at 1 year after surgery.</p><p><b>Results:</b> Of the 334 patients in the study, 280 patients showed a normal to a mildly impaired right ventricular function preoperatively (group 1). Fifty-four patients presented with moderate to severe right ventricular dysfunction (group 2). Patients with a compromised right ventricular function were more likely to undergo MVR (28.6% versus 53.7%, <i>P</i> <.001). The mean pulmonary artery pressure was 23.6 mm Hg in group 1 and 34 mm Hg in group 2 (<i>P</i> <.001). The left atrial diameter was 4.6 cm in group 1 and 5.3 cm in group 2 (<i>P</i> <.001). The 2 groups were not different with respect to operative mortality, but the patients in group 2 experienced more transfusion of blood products (588.4 mL versus 1180.6 mL, <i>P</i> <.001), longer intensive care unit stays (83.9 versus 149.6 hours, <i>P</i> <.001), and hospital stays (8.9 versus 12.8 days, <i>P</i> = .005). The rate of postoperative MV regurgitation was significantly higher in group 2 (1.8 versus 14.8%, <i>P</i> <.001). The overall 1-year survival rate was 92.5% in group 1 and 94.5% in group 2 (<i>P</i> = .59).</p><p><b>Conclusions:</b> This study has shown that a dysfunctional preoperative right ventricular function uses more resources and is associated with postoperative MV regurgitation, but it is not associated short- and mid-term mortality after MV surgery.</p>

Right ventricular systolic function in organic mitral regurgitation: impact of biventricular impairment

BACKGROUND

To assess the prevalence, determinants, and prognosis value of right ventricular (RV) ejection fraction (EF) impairment in organic mitral regurgitation.

METHODS AND RESULTS

Two hundred eight patients (62±12 years, 138 males) with chronic organic mitral regurgitation referred to surgery underwent an echocardiography and biventricular radionuclide angiography with regional function assessment. Mean RV EF was 40.4±10.2%, ranging from 10% to 65%. RV EF was severely impaired (≤35%) in 63 patients (30%), and biventricular impairment (left ventricular EF<60% and RV EF≤35%) was found in 34 patients (16%). Pathophysiologic correlates of RV EF were left ventricular septal function (β=0.42, P<0.0001), left ventricular end-diastolic diameter index (β=-0.22, P=0.002), and pulmonary artery systolic pressure (β=-0.14, P=0.047). Mitral effective regurgitant orifice size (n=84) influenced RV EF (β=-0.28, P=0.012). In 68 patients examined after surgery, RV EF increased strongly (27.5±4.3-37.9±7.3, P<0.0001) in patients with depressed RV EF, whereas it did not change in others (P=0.91). RV EF ≤35% impaired 10-year cardiovascular survival (71.6±8.4% versus 89.8±3.7%, P=0.037). Biventricular impairment dramatically reduced 10-year cardiovascular survival (51.9±15.3% versus 90.3±3.2%, P<0.0001; hazard ratio, 5.2; P<0.0001) even after adjustment for known predictors (hazard ratio, 4.6; P=0.004). Biventricular impairment reduced also 10-year overall survival (34.8±13.0% versus 72.6±4.5%, P=0.003; hazard ratio, 2.5; P=0.005) even after adjustment for known predictors (P=0.048).

CONCLUSIONS

In patients with organic mitral regurgitation referred to surgery, RV function impairment is frequent (30%) and depends weakly on pulmonary artery systolic pressure but mainly on left ventricular remodeling and septal function. RV function is a predictor of postoperative cardiovascular survival, whereas biventricular impairment is a powerful predictor of both cardiovascular and overall survival.

Comparison of right ventricular functional response to exercise in hypertrophic versus idiopathic dilated cardiomyopathy

Although the biventricular nature of the disease has been confirmed by morphologic studies, information on right ventricular (RV) function in hypertrophic cardiomyopathy (HC) is lacking. The aim of the study was to hemodynamically characterize RV performance in HC versus idiopathic dilated cardiomyopathy (IDC) during exercise. The hemodynamic data of 63 patients with HC who underwent hemodynamic exercise testing with thermodilution-derived assessment of RV ejection fraction were analyzed. The results were compared to a healthy control group (n = 20) and to patients with IDC (n = 86). The baseline RV ejection fraction was increased in the patients with HC compared to those with IDC (39 +/- 10% vs 33 +/- 12%; p = 0.002), but did not differ compared to controls (42 +/- 7% vs 39 +/- 10%; p = NS). An increase in end-diastolic volume from rest to exercise contributed to stroke volume augmentation in those with HC (121 +/- 38 vs 136 +/- 55 ml/m(2); p = 0.01) and control subjects (116 +/- 34 vs 138 +/- 31 ml/m(2); p = 0.002) but not in those with IDC (117 +/- 47 vs 120 +/- 52 ml/m(2); p = NS). At peak exercise the RV ejection fraction in those with HC was reduced compared to that in the controls (45 +/- 11% vs 59% +/- 9%; p <0.001), but it was increased compared to that in those with IDC (45 +/- 11% vs 35% +/- 11%; p <0.001). In conclusion, the extent of the pulmonary pressure increase was more pronounced in those with HC than in those with IDC, but the degree of functional impairment of the right ventricle was less severe, probably owing to its ability to recruit preload and contractile reserve with exercise.

Right ventricular myocardial performance index predicts perioperative mortality or circulatory failure in high-risk valvular surgery

BACKGROUND

The prognostic value of right ventricular myocardial performance index (RVMPI) and right ventricular fractional area change (RVFAC) in mitral or aortic valve surgery has not been well described. The main objective of this study is to assess the prognostic value of RVMPI and RVFAC in predicting postoperative mortality or circulatory failure.

METHODS

RVMPI and RVFAC were prospectively measured after induction of anesthesia using transesophageal echocardiography in 50 consecutive patients undergoing corrective mitral or aortic valve surgery. Univariate and multivariate analyses were performed for the primary clinical end point of in-hospital mortality or circulatory failure.

RESULTS

In the study population, the mean age was 67 +/- 9 years. The primary end point occurred in 17 patients (34%); three patients died, and 14 patients presented signs of circulatory failure. Multivariate regression analysis identified RVMPI and RVFAC as variables of prognostic significance.

CONCLUSION

Preoperative RVMPI and RVFAC could have an incremental value in predicting postoperative mortality and morbidity in valvular heart surgery. Future studies are needed to validate these results in a larger population.

Pulmonary pressure–flow relation as a determinant factor of exercise capacity and symptoms in patients with regurgitant valvular heart disease

BACKGROUND

Exertional dyspnea is a frequent limiting symptom in patients with chronic heart failure. Furthermore, dyspnea and a plateau in VO(2) (oxygen consumption) at peak exercise often co-exist in chronic heart failure, especially in patients with severe regurgitant valvular heart disease (RVHD), their relevance to hemodynamics and subjective symptoms during exercise have not been fully understood.

OBJECTIVES

The purpose of this study was to examine the determinant factor of exercise capacity in patients with RVHD.

METHODS

We performed a symptom-limited cardiopulmonary exercise test using a sitting cycle ergometer with right heart catheterization in 20 patients with severe RVHD. VO(2) and hemodynamics were measured at rest and during exercise, and symptomatic end-point at peak exercise was evaluated by using Borg's score.

RESULTS

Of the 20 patients, 11 attained a plateau in VO(2) at peak exercise (Group 1). At peak exercise, pulmonary arterial pressure (PAP) was higher, and cardiac output (CO) and VO(2) were lower in Group 1 than in patients without a plateau in VO(2) (Group 2) (mean PAP: 60+/-10 vs. 48+/-9 mm Hg, P=0.05; CO: 8.3+/-2.6 vs. 11.2+/-2.6 l/min, P=0.01; VO(2): 1059+/-259 vs. 1359+/-328 ml/min, P=0.01). In Group 1, 6 patients complaining of dyspnea rather than leg fatigue at peak exercise had lower CO (7.1+/-1.8 vs. 9.7+/-3.0 l/min, P=0.05) and higher slope of mean PAP-CO relation (P-Q slope) (10.6+/-3.6 vs. 5.4+/-1.7, P=0.01), compared with the other 5 patients with leg fatigue.

CONCLUSIONS

Development of pulmonary hypertension during exercise is the important limiting factor for exercise capacity in patients with RVHD. The limitation of increase in CO concomitant with pulmonary hypertension could be an important factor in the appearance of dyspnea.

Effects of pacing tachycardia and balloon valvuloplasty on pulmonary artery impedance and hydraulic power in mitral stenosis

BACKGROUND

Mitral stenosis is characterized by progressive pulmonary hypertension and eventual right ventricular failure. However, the correlation between right ventricular failure and the level of pulmonary hypertension is poor, suggesting that factors other than those recognized from nonpulsatile hemodynamic parameters may contribute to impaired right ventricular performance in this condition.

METHODS AND RESULTS

We studied 16 patients with severe mitral stenosis (mean valve area, 1.0 +/- 0.2 cm2) at supine rest and during pacing tachycardia using high-fidelity catheter recordings of pulmonary artery (PA) pressure and flow velocity. Pulmonary impedance spectra, wave reflection properties, and hydraulic power data were derived from Fourier analysis of signal-averaged data. Pacing tachycardia (baseline heart rate, 81 +/- 11 beats per minute; pacing, 132 +/- 11 beats per minute) significantly raised pulmonary wedge and mean PA pressures. There was no change in pulmonary vascular resistance (209 +/- 144 to 232 +/- 164 dyne-sec/cm5) or PA characteristic impedance (62 +/- 25 to 55 +/- 28 dyne-sec/cm5). However, first harmonic impedance (Z1) significantly decreased (134 +/- 71 to 100 +/- 68 dyne-sec/cm5; p < 0.001). Accordingly, oscillatory and total dissipated hydraulic power per unit forward flow (WT/CO) fell during tachycardia (2.6 +/- 1.6 to 2.3 +/- 1.4 mW/ml.sec-1; p = 0.06) despite acute pulmonary hypertension. Reflected pressure waves returned earlier to the proximal PA, suggesting increased vessel stiffness. Immediately after percutaneous balloon mitral valvuloplasty (PBV) in eight of the patients, baseline and pacing data were again recorded. Compared with the pre-PBV baseline state, post-PBV resting data demonstrated no change in resistance or characteristic impedance, but there was a significant fall in Z1 (166 +/- 75 to 103 +/- 45 dyne-sec/cm5; p < 0.05) and in the magnitude of pulmonary wave reflections. WT/CO tended to decrease after PBV, and pacing after PBV produced a further decrease in WT/CO, again in association with lower Z1.

CONCLUSIONS

These data demonstrate that 1) increased pulmonary characteristic impedance, although a feature of mitral stenosis, is not exacerbated by the acute effects of increased distending pressure; 2) pacing tachycardia in mitral stenosis causes little change in the pulmonary impedance spectrum except at low frequencies, where decreased impedance lowers power requirements per unit flow; and 3) relief of mitral stenosis produces immediate improvement in low-frequency impedance and in hydraulic power requirements. These findings suggest that although characteristic impedance may be a measure of the long-term effects of pulmonary hypertension on the pulmonary circulation, acute increases and decreases in PA pressure produce effects on right ventricular load that are best described in terms of the low-frequency properties of the PA system. Improvement in low-frequency impedance diminishes hydraulic power requirements and thus reflects improved ventricular-vascular coupling, irrespective of distending PA pressure. Efforts to treat or prevent right heart failure in the presence of pulmonary hypertension should take account of the potential benefit of changes in low-frequency impedance characteristics of the pulmonary vascular bed.

Right ventricular systolic function during exercise with and without significant coronary artery disease

To evaluate the effects of exercise and coronary artery disease on right ventricular (RV) systolic function, rest and exercise biplane RV angiograms were recorded in 20 patients undergoing diagnostic cardiac catheterization. Thirteen patients had exercise angiograms of sufficient quality to undergo analysis and were classified into 2 groups. Group 1 had no or only mild coronary artery disease; group 2 had significant coronary artery disease as manifested by new, exercise-induced, left ventricular regional wall motion abnormalities. RV systolic pressure increased in both groups during exercise: 33 to 57 mm Hg in group 1 (p = 0.0002) and 33 to 55 mm Hg in group 2 (p = 0.0004). Pulmonary resistance did not change in group 1 during exercise but increased in group 2 (3.2 to 4.8 Wood units, p = 0.04). RV ejection fraction increased slightly, but not significantly, during exercise in group 1, but decreased in group 2 (73 vs 58% with exercise [p = 0.01]). The change in RV ejection fraction from rest to exercise correlated closely with the change in pulmonary resistance from rest to exercise (r = -0.89, p less than 0.0001). RV regional wall motion analysis demonstrated a generalized decline in regional ejection fraction in group 2 during exercise, even in patients without right coronary artery disease. In conclusion, there is a decline in RV ejection fraction during exercise in patients with significant coronary artery disease. The generalized reduction in regional RV ejection fraction coupled with the close correlation with the change in pulmonary resistance suggests that increased afterload, rather than RV ischemia, is the cause.

Mitral regurgitation: relationship of noninvasive descriptors of right and left ventricular performance to clinical and hemodynamic findings and to prognosis in medically and surgically treated patients

To determine objective predictors of survival, 53 patients with chronic, hemodynamically severe mitral regurgitation underwent rest and exercise radionuclide cineangiography, echocardiography, treadmill exercise testing, and ambulatory electrocardiographic monitoring before prospective (average 30 month) follow-up. At entry, symptom status correlated best with radionuclide-based right ventricular ejection fraction (RVEF) and left atrial size, while treadmill exercise tolerance correlated best with RVEF during exercise (r = .48, p less than .005). Correspondingly, in 23 patients who underwent cardiac catheterization, pulmonary arterial systolic and wedge pressures were significantly inversely related to RVEF. On the 24 hr ambulatory electrocardiogram, nonsustained ventricular tachycardia was present in 29% of patients, most frequently when both RVEF and left ventricular ejection fraction (LVEF) were subnormal (p = .03 vs other patients). Since entry, 35 patients have been managed without surgery for 9 to 57 months (average 28); three of these who subsequently underwent operation also are among the 21 patients who have undergone mitral valve replacement (MVR). During the average 28 months of observation under medical treatment five of 35 nonoperated patients have died; all five were among the six nonoperated patients with RVEFs of 30% or less at entry, a descriptor that significantly identified those at high mortality risk (p less than .0001 vs patients with RVEFs greater than 30%). All five also were among the eight nonoperated patients with LVEFs of 45% or less (lower limit of normal), a descriptor that also significantly predicted mortality. Three of the 21 patients who underwent surgery have died, all late after MVR. Among operated patients, only age was a predictor of postoperative survival. A trend toward improved survival was found in the patients with depressed right or left ventricular ejection fraction who underwent surgery compared with those who did not.