Pulmonary artery pressure and pulmonary vascular resistance before and after mitral balloon valvotomy in 100 patients with severe mitral valve stenosis

The effects of mitral stenosis on right ventricular mechanics assessed by three-dimensional echocardiography

Mitral stenosis (MS) is a complex valvular pathology with significant clinical burden even today. Its effect on the right heart is often overlooked, despite it playing a considerable part in the symptomatic status. We enrolled 39 mitral valve stenosis patients and 39 age- and gender-matched healthy controls. They underwent conventional, speckle-tracking and 3D echocardiographic examinations. The 3D data was analyzed using the ReVISION software to calculate RV functional parameters. In the MS group, 3D RV ejection fraction (EF) (49 ± 7% vs. 61 ± 4%; p < 0.001), global circumferential (GCS) (- 21.08 ± 5.64% vs. - 25.07 ± 4.72%; p = 0.001) and longitudinal strain (GLS) (- 16.60% ± 4.07% vs. - 23.32 ± 2.82%; p < 0.001) were reduced. When comparing RV contraction patterns between controls, MS patients in sinus rhythm and those with atrial fibrillation, radial (REF) (32.06 ± 5.33% vs. 23.62 ± 7.95% vs. 20.89 ± 6.92%; p < 0.001) and longitudinal ejection fraction (LEF) (24.85 ± 4.06%; 17.82 ± 6.16% vs. 15.91 ± 4.09%; p < 0.001) were decreased in both MS groups compared to controls; however, they were comparable between the two MS subgroups. Anteroposterior ejection fraction (AEF) (29.16 ± 4.60% vs. 30.87 ± 7.71% vs. 21.48 ± 6.15%; p < 0.001) showed no difference between controls and MS patients in sinus rhythm, while it was lower in the MS group with atrial fibrillation. Therefore, utilizing 3D echocardiography, we found distinct morphological and functional alterations of the RV in MS patients.

2023 Korean Society of Echocardiography position paper for the diagnosis and management of valvular heart disease, part II: mitral and tricuspid valve disease

This manuscript represents the official position of the Korean Society of Echocardiography on valvular heart diseases. This position paper focuses on the diagnosis and management of valvular heart diseases with referring to the guidelines recently published by the American College of Cardiology/American Heart Association and the European Society of Cardiology. The committee sought to reflect national data on the topic of valvular heart diseases published to date through a systematic literature search based on validity and relevance. In the part II of this article, we intend to present recommendations for diagnosis and treatment of mitral valve disease and tricuspid valve disease.

Pulmonary hypertension secondary to valvular heart disease: a state-of-the-art review

Pulmonary hypertension (PH) is a common disease affecting up to 1% of the population and at least 50% of patients diagnosed with heart failure (HF) (Hoeper et al. in Lancet Respir Med 4(4):306-322, 2016). It is estimated that PH is present in 15% to 60% of patients with valvular heart disease (VHD) which can result from an increase in pulmonary blood flow and subsequently in pulmonary venous congestion and pulmonary vascular resistance (PVR). It is important to identify the severity of PH in patients with VHD to appropriately risk stratify and manage these patients (Magne et al. in JACC Cardiovasc Imaging 8(1):83-99, 2015). In this review, we examine the diagnostic criteria for PH and its pathophysiology. We also focus on the growing evidence supporting the presence of PH secondary to VHD and describe the contemporary surgical and medical therapeutic interventions in this patient population (Fig. 1).

Hemodynamic Characteristics and Outcomes of Pulmonary Hypertension in Patients Undergoing Tricuspid Valve Repair or Replacement

BACKGROUND

The impact of pulmonary hypertension (PH) on outcomes after surgical tricuspid valve replacement (TVR) and repair (TVr) is unclear. We sought to characterize PH in patients undergoing TVR/TVr, based on invasive hemodynamics and evaluate the effect of PH on mortality.

METHODS

We identified 86 consecutive patients who underwent TVR/TVr with invasive hemodynamic measurements within 3 months before surgery. We used Kaplan-Meier survival and restricted mean survival time (RMST) analyses to quantify the effects of PH on survival.

RESULTS

The mean age was 63 ± 13 years, 59% were female, 45% had TVR, 55% had TVr, 39.5% had isolated TVR/TVr, and 60.5% had TVR/TVr concomitant with other cardiac surgeries). Eighty-six percent of these patients had PH with a mean pulmonary artery pressure of 30 ± 10 mm Hg, pulmonary vascular resistance (PVR) of 2.5 (interquartile range: 1.5-3.9) Wood units (WU), pulmonary arterial compliance of 2.3 (1.6-3.6) mL/mm Hg, and pulmonary arterial elastance of 0.8 (0.6-1.2) mm Hg/mL. Cardiac output was mildly reduced at 4.0 ± 1.4 L/min, with elevated right-atrial pressure (14 ± 12 mm Hg) and pulmonary capillary wedge pressure (19 ± 7 mm Hg). Over a median follow-up of 6.3 years, 22% of patients died. Patients with PVR ≥ 2.5 WU had lower RMST over 5 years compared with patients with PVR < 2.5 WU.

CONCLUSION

PH is common in patients undergoing TVR/TVr, with combined pre- and postcapillary being the most common type. PVR ≥ 2.5 WU is associated with lower survival at 5-year follow-up.

Stressing the Cardiopulmonary Vascular System: The Role of Echocardiography

The cardiopulmonary vascular system represents a key determinant of prognosis in several cardiorespiratory diseases. Although right heart catheterization is considered the gold standard for assessing pulmonary hemodynamics, a comprehensive noninvasive evaluation including left and right ventricular reserve and function and cardiopulmonary interactions remains highly attractive. Stress echocardiography is crucial in the evaluation of many cardiac conditions, typically coronary artery disease but also heart failure and valvular heart disease. In stress echocardiographic applications beyond coronary artery disease, the assessment of the cardiopulmonary vascular system is a cornerstone. The possibility of coupling the left and right ventricles with the pulmonary circuit during stress can provide significant insight into cardiopulmonary physiology in healthy and diseased subjects, can support the diagnosis of the etiology of pulmonary hypertension and other conditions, and can offer valuable prognostic information. In this state-of-the-art document, the topic of stress echocardiography applied to the cardiopulmonary vascular system is thoroughly addressed, from pathophysiology to different stress modalities and echocardiographic parameters, from clinical applications to limitations and future directions.

Pulmonary vascular resistance and proper timing of percutaneous balloon mitral valvotomy

It is frequent to see pulmonary hypertension (PH) in patients with mitral stenosis (MS) secondary to increased pulmonary vascular resistance (PVR), data about the effect of PVR on the results of percutaneous balloon mitral valvotomy (PBMV) are insufficient. To detect the role of PVR in predicting residual PH immediately after PBMV. This prospective study comprised 49 consecutive patients with moderate to severe MS who were investigated pre and within 48 h post a successful PBMV for the first time. Echocardiography was used to assess the mitral valve area (MVA), mean transmitral pressure gradient (MPG), mitral valve resistance (MVR), right ventricular systolic pressure (RVSP) and PVR. Patients were classified into two groups according to the pre PVR (≥ 1.6 WU as group I and < 1.6 as group II). At baseline compared to group II (32 patients), Group I (17 patients) had higher MPG (13.6 ± 5.2 vs. 11.7 ± 3.7 mmHg, P < 0.05), RVSP (45.6 vs. 37.9 mmHg, P < 0.001) and PVR (2.2 ± 0.1 vs. 1.2 ± 0.1WU, P < 0.001) with no significant difference regarding age, gender, MVS, MVA and MVR. Patients of group I had comparatively lower improvement immediate post procedural of RVSP and PVR with no significant difference in immediate post procedural improvement in NYHA classification, MVA, MPG and MVR. Basal PVR > 1.8WU was proved to be a highly specific (91%), a good predictor (AUC 0.78) of persistent elevation of RVSP > 50 mmHg post PMV. Pathological rise of PVR that associates MS had provided a strong and an independent predictor of persistent pulmonary hypertension post PBMV and by this aspect it could be used as a valuable tool as MVA and MPG to send patients earlier for PBMV even with less severe MS. PVR > 1.81 WU could be used as a noninvasive parameter for predicting regression of PH immediately after PBMV.

"Left ventricular filling pressure(s)" - Ambiguous and misleading terminology, best abandoned

The use of the terms "left ventricular filling pressure" and "left ventricular filling pressures" is widespread in the cardiology literature, but the meanings ascribed to these terms have not been consistent. Left ventricular end-diastolic pressure (LVEDP) and mean left atrial pressure (LAP) cannot be used interchangeably as they will often differ in magnitude in the presence of cardiac disease and they also have different clinical significance. LVEDP is the best pressure to use when considering left ventricular function, whereas mean LAP is the most relevant pressure when considering the tendency to pulmonary congestion. The mean LAP is also the most relevant pressure for determining whether pulmonary hypertension has a left heart (post-capillary) component. If only a left ventricular pressure tracing is available then a technique to measure the mean left ventricular diastolic pressure is the best option for estimating the mean LAP. If only right heart pressures are available then the pulmonary artery end-diastolic pressure will provide a reasonable estimate of LVEDP, but only when the heart and pulmonary circulation are normal. If there is mitral valve disease, left ventricular disease or pulmonary hypertension the LVEDP cannot be estimated from right heart pressures. The problem of the ambiguity of "filling pressure (s)" is readily solved by the abandonment of this term and the use of either LVEDP or mean LAP as appropriate.

Pulmonary hypertension caused by pulmonary venous hypertension

The effect of pulmonary venous hypertension (PVH) on the pulmonary circulation is extraordinarily variable, ranging from no impact on pulmonary vascular resistance (PVR) to a marked increase. The reasons for this are unknown. Both acutely reversible pulmonary vasoconstriction and pathological remodeling (especially medial hypertrophy and intimal hyperplasia) account for increased PVR when present. The mechanisms involved in vasoconstriction and remodeling are not clearly defined, but increased wall stress, especially in small pulmonary arteries, presumably plays an important role. Myogenic contraction may account for increased vascular tone and also indirectly stimulate remodeling of the vessel wall. Increased wall stress may also directly cause smooth muscle growth, migration, and intimal hyperplasia. Even long-standing and severe pulmonary hypertension (PH) usually abates with elimination of PVH, but PVH-PH is an important clinical problem, especially because PVH due to left ventricular noncompliance lacks definitive therapy. The role of targeted PH therapy in patients with PVH-PH is unclear at this time. Most prospective studies indicate that these medications are not helpful or worse, but there is ample reason to think that a subset of patients with PVH-PH may benefit from phosphodiesterase inhibitors or other agents. A different approach to evaluating possible pharmacologic therapy for PVH-PH may be required to better define its possible utility.

Persistent pulmonary artery hypertension in patients undergoing balloon mitral valvotomy

Pulmonary artery pressure (PAP) is known to regress after successful balloon mitral valvotomy (BMV). Data of persistent pulmonary artery hypertension (PPAH) following BMV is scarce. We analyzed the clinical, echocardiographic, and hemodynamic data of 701 consecutive patients who have undergone successful BMV in our institute from 1997 to 2003. Data of 287 patients who had PPAH (defined by pulmonary artery systolic pressure [PASP] of ≥ 40 mmHg at one year following BMV) were compared to the data of 414 patients who did not have PPAH. Patients who had PPAH were older (39.9 ± 9.9 years vs. 29.4 ± 10.1; P < 0.001). They had higher prevalence of atrial fibrillation (AF; 21.9 vs. 12.1%, P < 0.05), moderate or severe pulmonary artery hypertension (PAH) defined as PASP more than 50 mmHg (43.5 vs. 33.8%, P = 0.00), anatomically advanced mitral valve disease as assessed by Wilkin's echocardiographic score > 8 (33.7 vs. 23.2%, P < 0.001), and coexistent aortic valve disease (45.6 vs. 37.9%, P < 0.001) at the baseline. Those patients with PPAH had comparatively lower immediate postprocedural mitral valve area (MVA). On follow-up of more than five years, the occurrence of restenosis (39.3 vs. 10.1%, P = 0.000), new onset heart failure (14% vs. 4%, P < 0.05) and need for reinterventions (9.5% vs. 2.8%, P < 0.05) were higher in the PPAH group. Patients with PPAH were older, sicker, and had advanced rheumatic mitral valve disease. They had higher incidence of restenosis, new onset heart failure, and need for reinterventions on long term follow-up. PPAH represents an advanced stage of rheumatic valve disease and indicates chronicity of the disease, which may be the reason for the poorer prognosis of these patients. Patients with PPAH requires intense and more frequent follow-up.

Percutaneous Mitral Valve Interventions

Percutaneous interventions for mitral valve disease represent both the oldest and the newest of catheter interventions. Balloon mitral valvuloplasty was among the first effective catheter therapies for valvular heart disease. The technique and device approach was initially reported by Inoue in 1982 and, remarkably, is virtually unchanged between then and now. Conversely, novel catheter therapies to repair mitral regurgitation are now in their infancy, with only the earliest human experience. This article details the spectrum of these therapies.

Pulmonary blood flow and pulmonary hypertension: Is the pulmonary circulation flowophobic or flowophilic?

Increased pulmonary blood flow (PBF) is widely thought to provoke pulmonary vascular obstructive disease (PVO), but the impact of wall shear stress in the lung is actually poorly defined. We examined information from patients having cardiac lesions which impact the pulmonary circulation in distinct ways, as well as experimental studies, asking how altered hemodynamics impact the risk of developing PVO. Our results are as follows: (1) with atrial septal defect (ASD; increased PBF but low PAP), shear stress may be increased but there is little tendency to develop PVO; (2) with normal PBF but increased pulmonary vascular resistance (PVR; mitral valve disease) shear stress may also be increased but risk of PVO still low; (3) with high PVR and PBF (e.g., large ventricular septal defect), wall shear stress is markedly increased and the likelihood of developing PVO is much higher than with high PBF or PAP only; and (4) with ASD, experimental and clinical observations suggest that increased PBF plus another stimulus (e.g., endothelial inflammation) may be required for PVO. We conclude that modestly increased wall shear stress (e.g., ASD) infrequently provokes PVO, and likely requires other factors to be harmful. Likewise, increased PAP seldom causes PVO. Markedly increased wall shear stress may greatly increase the likelihood of PVO, but we cannot discriminate its effect from the combined effects of increased PAP and PBF. Finally, the age of onset of increased PAP may critically impact the risk of PVO. Some implications of these observations for future investigations are discussed.

The impact of pulmonary venous hypertension on the pulmonary circulation in the young

OBJECTIVE AND DESIGN

Pulmonary venous hypertension is a well-characterized cause of pulmonary hypertension in adults, but little is known regarding the relationship between left atrial pressure and pulmonary arteriolar resistance in the young. Also, in adults relief of pulmonary venous hypertension results in a marked fall in pulmonary arteriolar resistance, but this could be different in children because vascular changes are more severe in young patients than adults with mitral stenosis. We inspected records of children at Children's Hospital Boston having mitral balloon valvuloplasty, and patients ≤5 years old having mitral valve replacement, to determine (1) the relationship between left atrial pressure and pulmonary arterial pressure and resistance (n = 94 children, median age 17.8 months) and (2) how pulmonary arteriolar resistance changes after mitral valve replacement.

RESULTS

The average indexed pulmonary arteriolar resistance was 7.8 ± 5.9 units and was unrelated to age but was positively related to left atrial pressure. There was great variability in pulmonary arteriolar resistance for any given left atrial pressure. Pulmonary arterial pressure (n = 16) and pulmonary arterial resistance (n = 9) were measured before and after mitral valve replacement (median = 29.4 months old). Despite preoperative indexed pulmonary arterial resistance of ≥5 units in 11 of 15 patients, postoperative pulmonary arterial pressure was substantially lower in all save three, and two patients with high pulmonary arterial pressure still had high left atrial pressure postoperatively (25 mmHg).

CONCLUSIONS

We conclude that in young children, as in adults, pulmonary arterial resistance generally falls greatly with reduction in left atrial pressure.

Pulmonary hypertension related to left-sided cardiac pathology

Pulmonary hypertension (PH) is the end result of a variety of diverse pathologic processes. The chronic elevation in pulmonary artery pressure often leads to right ventricular pressure overload and subsequent right ventricular failure. In patients with left-sided cardiac disease, PH is quite common and associated with increased morbidity and mortality. This article will review the literature as it pertains to the epidemiology, pathogenesis, and diagnosis of PH related to aortic valve disease, mitral valve disease, left ventricular systolic and diastolic dysfunction, and pulmonary veno-occlusive disease. Moreover, therapeutic strategies, which focus on treating the underlying cardiac pathology will be discussed.

Hemodynamic effects of inhaled nitric oxide in women with mitral stenosis and pulmonary hypertension

Mitral stenosis (MS) is associated with elevated left atrial pressure, increased pulmonary vascular resistance (PVR), and pulmonary hypertension (PH). The hemodynamic effects of inhaled nitric oxide (NO) in adults with MS are unknown. We sought to determine the acute hemodynamic effects of inhaled NO in adults with MS and PH. Eighteen consecutive women (mean age 58 +/- 15 years) with MS and PH underwent heart catheterization. Hemodynamic measurements were recorded at baseline, after NO inhalation at 80 ppm, and after percutaneous balloon valvuloplasty (n = 10). NO reduced pulmonary artery systolic pressure (62 +/- 14 mm Hg [baseline] vs 54 +/- 15 mm Hg [NO]; p <0.001) and PVR (3.7 +/- 2.5 Wood U [baseline] vs 2.2 +/- 1.4 Wood U [NO]; p <0.001). NO had no effect on mean aortic pressure, left ventricular end-diastolic pressure, left atrial pressure, cardiac output, or systemic vascular resistance. Mitral valve area increased after valvuloplasty (0.9 +/- 0.2 cm2 [baseline] vs 1.6 +/- 0.3 cm2 [postvalvuloplasty]; p <0.001). A decrease in left atrial pressure (25 +/- 4 mm Hg [baseline] vs 17 +/- 4 mm Hg [after valvuloplasty]; p <0.001) and pulmonary artery systolic pressure (58 +/- 12 mm Hg [baseline] vs 45 +/- 8 mm Hg [after valvuloplasty]; p <0.001) was observed after valvuloplasty. No change in cardiac output or PVR was observed. Thus inhaled NO, but not balloon valvuloplasty, acutely reduced PVR in women with MS and PH. This suggests that a reversible, endothelium-dependent regulatory abnormality of vascular tone is an important mechanism of elevated PVR in MS.

Factors determining normalization of pulmonary vascular resistance following successful balloon mitral valvotomy

Balloon mitral valvotomy (BMV) provides improvement in pulmonary vascular resistance (PVR) in patients with severe mitral stenosis. Its normalization, however, remains questionable. We evaluated PVR before, after BMV, and at follow-up in 37 patients who had a previous successful BMV. Patients were divided into 2 groups: group 1 had 21 patients with normalized PVR (<125 dynes/s/cm5) either after BMV or at follow-up, and group 2 had 16 patients with persistently abnormal PVR. Patients in group 2 were older than patients in group 1 (55+/-13 vs 43+/-14 years, p = 0.01) and had atrial fibrillation more frequently (10 [63%] vs 6 [29%], p = 0.04). Age, cardiac rhythm, mitral valve area, pulmonary bed gradient, pulmonary artery pressure, and PVR before the procedure were significant univariate predictors for normalization of PVR. Age, echocardiographic score, systolic pulmonary artery pressure, and mitral regurgitation were all independent determinants of normalization of PVR in a multivariate logistic regression model. We conclude that PVR failed to return to normal in 16 patients (43%) after successful BMV; this can be predicted by baseline clinical and hemodynamic parameters.

Immediate and long-term effect of mitral balloon valvotomy on severe pulmonary hypertension in patients with mitral stenosis

The pulmonary vascular hemodynamics were studied in 21 patients with severe mitral stenosis and severe pulmonary hypertension. Hemodynamic data were obtained before and immediately after mitral balloon valvotomy (MBV) and at follow-up 7 to 14 months (mean 12 months) later by repeat catheterization. The mean pulmonary capillary wedge pressure (PCW) decreased from 27 +/- 5 to 15 +/- 4 mm Hg (p < 0.001). The mean mitral valve gradient (MVG) decreased from 18 +/- 4 to 6 +/- 2 mm Hg (p < 0.001). Mitral valve area (MVA) increased from 0.6 +/- 0.1 to 1.5 +/- 0.3 cm2 (p < 0.02). Cardiac index increased from 2.2 +/- 0.3 to 2.6 to 0.5 L/min/m2 (p < 0.02). The pulmonary artery systolic pressure decreased from 65 +/- 13 to 50 +/- 13 mm Hg (p < 0.001), and no significant change was seen in pulmonary vascular resistance (PVR) immediately after MBV from 461 +/- 149 to 401 +/- 227 dynes/sec/cm(-5) (p = 0.02). At follow-up the MVA increased from 1.5 +/- 0.3 to 1.7 +/- 0.3 cm2 (p < 0.02). Cardiac index increased further to 3 +/- 0.4 L/min/m2 (p < 0.02). MVG and PCW pressure remained the same. The pulmonary artery systolic pressure decreased further to 38 +/- 9 mm Hg (p < 0.02). PVR decreased significantly to 212 +/- 99 dynes/sec/cm(-5) (p < 0.02). We concluded that the pulmonary artery pressure decreased without normalizing immediately after MBV and normalized in patients with optimal results from mitral balloon valvotomy 7 to 14 months later. Insignificant change in PVR was seen immediately after MBV and markedly decreased or normalized at late follow-up in patients with optimal result from MBV.

Balloon mitral valvotomy in patients with systemic and suprasystemic pulmonary artery pressures

Mitral stenosis with severe pulmonary artery hypertension constitutes a high risk subset for surgical commissurotomy or valve replacement. Balloon mitral valvotomy has been proposed as a technique for treating high risk surgical patients with mitral stenosis. The efficacy of this technique in patients with severe pulmonary artery hypertension, however, has not been fully evaluated. Percutaneous transvenous mitral commissurotomy (PTMC) was performed in 450 consecutive patients. Of these, forty-five (10%) patients had systemic or suprasystemic systolic pulmonary artery pressures (110 +/- 20, range 96 to 170 mm Hg). The baseline characteristics and immediate hemodynamic results of these 45 patients with systemic/suprasystemic systolic pulmonary artery pressures (group I) were analysed and compared with those of 405 patients with subsystemic systolic pulmonary artery pressures (group II). Patients in group I were more symptomatic (New York Heart Association functional class > or = III, 96 vs. 55%, P < 0.001) and had severe subvalvular fibrosis (mitral subvalvular distance ratio [MSDR], 0.14 +/- 0.04 vs. 0.22 +/- 0.04, P < 0.01). Before PTMC, mean transmitral gradient was higher (34 +/- 8 vs. 25 +/- 4 mm Hg, P < 0.02) and mitral valve area smaller (0.5 +/- 0.3 vs. 0.9 +/- 0.4 cm2, P < 0.02) in group I patients, who also had higher pulmonary vascular resistance (16 +/- 5 vs. 9 +/- 5 U, P < 0.005). After PTMC final mean transmitral gradients (7 +/- 3 vs. 5 +/- 3 mm Hg) and mitral valve areas (1.9 +/- 0.4 vs. 2.0 +/- 0.4 cm2) were similar in both groups (P = NS). Group I patients had a greater decrease in pulmonary artery pressures (34 +/- 4 vs. 25 +/- 2%, P < 0.05) but final systolic pulmonary artery pressures (82 +/- 20 vs. 50 +/- 14 mm Hg) and pulmonary vascular resistance (12 +/- 4 vs. 6 +/- 4 U) remained significantly higher in this group (P < 0.005). Thus, in patients with severe pulmonary artery hypertension, PTMC is a safe and effective technique providing good immediate hemodynamic results.