Mitral valve surgery in the presence of pulmonary hypertension

Measurement of Pulmonary Artery Wave Reflection Before and After Mitral Valvuloplasty in Canine Patients With Pulmonary Hypertension Caused by Myxomatous Mitral Valve Disease

Background: Pulmonary arterial wave reflection provides novel information about pulmonary artery hemodynamics in pulmonary hypertension (PH). PH is common in dogs with myxomatous mitral valve disease (MMVD), though research examining the relationship between pulmonary arterial wave reflection and MMVD with PH is lacking. Hypothesis/Objective: This study investigated conventional echocardiographic parameters and pulmonary artery wave reflection parameters before and after mitral valvuloplasty in canine patients with PH due to MMVD. The parameters were backward pressure (Pb), forward pressure (Pf), and the reflection coefficient calculated as the ratio of peak Pb to peak Pf (RC). Animals: The study subjects were 10 client-owned dogs receiving mitral valvuloplasty for MMVD with PH. Methods: Conventional echocardiographic parameters and pulmonary artery wave reflection parameters were measured before and after mitral valvuloplasty. The relationships between pulmonary artery wave reflection parameters and echocardiographic parameters, estimation of pulmonary artery systolic pressure, and right atrium pressure (RAP) gained by catheter in mitral valvuloplasty were also investigated. Post-operative echocardiography and the measurement of pulmonary arterial wave reflection were performed 2 weeks after mitral valvuloplasty. Results: The parameters of normalized left ventricular internal diameter at end-diastole (LVIDDN), E velocity, and the estimation of pulmonary artery systolic pressure were significantly reduced post-operatively compared with baseline measurements (p < 0.05). Post-operative Pb decreased significantly compared with pre-operative measurements (8.8 ± 5.9 to 5.0 ± 3.2 mmHg, p = 0.037) as did RC (0.37 ± 0.15 to 0.22 ± 0.11, p < 0.01). A statistically significant positive correlation existed between wave reflection parameters and RAP, an estimation of pulmonary artery systolic pressure. Conclusions: Results demonstrate that mitral valvuloplasty can be used to treat secondary PH caused by MMVD, resulting in the improvement of post-operative echocardiographic and wave reflection parameters and a decrease in the right afterload. In some patients, some degree of vascular admittance mismatch persisted, despite the improvement of left atrial pressure. This may be indicative of residual pulmonary arterial disease, which may continue to adversely affect interactions between the right ventricle and the vasculature.

Outcomes of repeat mitral valve surgery in patients with pulmonary hypertension

OBJECTIVE

We sought to study the outcomes of redo-mitral valve surgery in patients with pulmonary hypertension.

METHODS

We reviewed data on redo mitral valve surgery in patients with pulmonary hypertension measured by Swan-Ganz catheter (mean pulmonary artery pressure ≥ 25 mm Hg or systolic pulmonary artery pressure ≥ 40 mm Hg).

RESULTS

Between 1996 and 2010, 637 patients underwent 658 redo mitral valve operations; 138 of them had pulmonary hypertension. The mean patient age was 61.3 (13.9) years, with mean left ventricular ejection fraction of 47.6% (13.2%). The mean systolic pulmonary artery pressure was 61.5 (16.8) mm Hg, and mean pulmonary artery pressure was 40.8 (11.6) mm Hg. Patients had one (71%, 98/138), two (23.9%, 33/138), and three (5.1%, 7/138) previous mitral valve operations. Thirty-day mortality was 10.1% (14/138). Multivariate predictors of 30-day mortality were chronic renal failure [odds ratio (OR), 8.041; P = 0.022], peripheral vascular disease (OR, 5.976; P = 0.025), previous mitral valve replacement (OR, 9.034; P = 0.014), and increasing age (OR, 1.077; P = 0.013). The severity of pulmonary hypertension did not impact 30-day (P = 0.314) or late mortality (P = 0.860). Kaplan-Meier survival rates at 1, 3, and 5 years were 76.6% (n = 99), 65.7% (n = 62), and 55.9% (n = 41), respectively.

CONCLUSIONS

Patients with pulmonary hypertension that undergo redo mitral valve surgery have a 55.9% 5-year survival rate. Increasing age, chronic renal insufficiency, peripheral vascular disease, and preexisting mitral valve prosthesis are associated with early mortality. The severity of pulmonary hypertension does not affect operative mortality rates, but it may decrease 1-, 3-, and 5-year survival.

Impact of pulmonary hypertension on the outcomes of noncardiac surgery: predictors of perioperative morbidity and mortality

OBJECTIVES

We sought to determine the predictors of short-term morbidity and mortality (< 30 days) after noncardiac surgery in patients with pulmonary hypertension (PH).

BACKGROUND

Pulmonary hypertension is considered to be a significant preoperative risk factor.

METHODS

The PH and surgical data bases were matched from 1991 to 2003. Patients were excluded if PH was secondary to left heart disease, not present before surgery, or the procedure involved cardiopulmonary bypass. Univariate and multivariate logistic regression analyses were used to identify variables associated with short-term morbidity and mortality.

RESULTS

Of 1,276 patients in the PH database, 145 patients (73% female) met all study criteria. The mean age (+/-SD) was 60.1 +/- 16.0 years. Right ventricular systolic pressure (RVSP) (mean +/- SD) on the two-dimensional echocardiogram was 68 +/- 21 mm Hg. There were 60 patients (42%) who experienced one or more short-term morbid event(s) (1.8 events/patient experiencing any event). A history of pulmonary embolism (p = 0.01), New York Heart Association functional class > or = II (p = 0.02), intermediate- to high-risk surgery (p = 0.04), and duration of anesthesia > 3 h (p = 0.04) were independent predictors of short-term morbidity. There were 10 early deaths (7%). A history of pulmonary embolism (p = 0.04), right-axis deviation (p = 0.02), right ventricular (RV) hypertrophy (p = 0.04), RV index of myocardial performance > or = 0.75 (p = 0.03), RVSP/systolic blood pressure > or = 0.66 (p = 0.01), intraoperative use of vasopressors (p < 0.01), and anesthesia when nitrous oxide was not used (p < 0.01) were each associated with postoperative mortality.

CONCLUSIONS

In patients with PH undergoing noncardiac surgery with general anesthesia, specific clinical, diagnostic, and intraoperative factors may predict worse outcomes.

High-risk mitral valve replacement in severe pulmonary hypertension--30 years experience

OBJECTIVE

In the past 30 years, 2316 patients underwent mitral valve replacement (MVR) at our institution; 382 of them had severe pulmonary hypertension (pulmonary artery pressure (PAP) > 50 mmHg; pulmonary vascular resistance (PVR), 690 +/- 46 dyn/s per m2). We reviewed our early and late results in this high-risk subgroup.

METHODS

We used 336 mechanical and 46 biological devices for MVR. The follow-up was 95%, with an observation period of 3208 patient-years and a mean of 8.4 +/- 0.2 years per patient. The overall early mortality rate was 10.5% (n = 40) and stayed at about the same level over the years, although patients characteristics have changed to much older patients and more reoperations. To clarify this fact we divided our data in results according to the decades in which the operations were carried out. The clinical preoperative status and results were as follows (*P < 0.05; **P < 0.01 compared with previous decade). In the decades between 1963 and 1973 (I), 1974 and 1983 (11) and 1984 and 1993 (III) we operated on n = 95 (I), n = 185 (II), and n = 102 (III) patients with a mean age of 43 +/- 1 (I), 50 +/- 1** (II), and 58 +/- 1** (III) years. The incidence of reoperations among these patients was 3.2 (I), 4.9 (II), and 22.6%** (III). The early mortalities were 13.7 (I), 8.6* (II) and 10.8% (III); late mortalities lowered from 5.77 (I), over 4.95 (II), and up to 3.39%** (III) patients/year. The mean functional status according to New York Heart Association (NYHA) class improved from preoperatively 3.0 +/- 0.1 (I), 3.2 +/- 0.1 (II) and 3.3 +/- 0.1 (III) to 2.4 +/- 0.2 (I), 2.4 +/- 0.1 (II) and 2.3 +/- 0.1 (III) postoperatively.

RESULTS

Compared with routine elective MVR with a mortality rate of 3.6% (P < 0.01), early mortality is high. But once the patient survives the perioperative course, late results show no difference compared with patients without pulmonary hypertension. The functional results as well are not significantly different. In spite of on average 15 years older multimorbid patients with therefore higher complication rates, early results improved slightly, which could be explained by better operative techniques, perioperative treatment and nursing (online monitoring with immediate therapeutic substitution). Surprisingly the increased number of reoperations had no negative impact on patients' outcomes.

CONCLUSION

According to our results, we recommend MVR in severe pulmonary hypertension even in the elderly, with a high but acceptable risk and good long-term results.

Assessment of operative risk for patients with advanced lung disease

Increasingly, patients with advanced lung disease are being offered operative procedures. The assessment of the perioperative risk of these patients must include not only the assessment of their lung disease, but the assessment of the patient's cardiovascular disease, their age, and their other medical problems. Knowledge of the stress of particular surgical procedures is also of importance in risk assessment, and is addressed in this article.