Abstract
Background
Mitral regurgitation (MR) is a common valvular disorder, occurring in up to 10% of the general population. Although surgery is the established treatment for primary MR, many patients do not receive appropriate therapy. The objective of this study was to determine the incidence and treatment pattern of patients with severe MR evaluated at a tertiary medical center and determine factors associated with receiving surgery.
Methods
All patients with moderate-severe and severe MR undergoing transthoracic echocardiography from 2011 to 2016 were identified. Patients with prior mitral valve surgery were excluded. Treatment recommendations were classified as referral to cardiology, referral to cardiothoracic surgery (CTS), receiving mitral valve surgery or receiving MitraClip. A multivariate logistic regression model was used to evaluate factors associated with referral to CTS or receiving surgery.
Results
During the study period, 1918 transthoracic echocardiogram were performed and 412 patients with moderate-severe or severe MR were identified. One hundred sixty-six patients (40%) had primary MR and 246 patients (60%) had secondary MR. For those with primary MR, 75 patients (45%) received treatment (surgery, n = 60 and MitraClip, n = 15) and 91 patients (55%) did not receive treatment. One hundred patients (60%) were referred to CTS and 128 patients (77%) were referred to cardiology. Patients undergoing surgery were younger (62.6 ± 14.2 years vs 72.0 ± 14 years, p < 0.001), with a higher prevalence of heart failure (57% vs 40%, p = 0.044) and a lower prevalence of stroke (3% vs 24%, p < 0.001) and hypertension (54% vs 74%, p = 0.012), compared to patients not undergoing surgery, respectively. Ejection fraction (60.4 ± 10.9% vs 56.3 ± 11.6%, p = 0.034), left ventricular end diastolic diameter (53.2 ± 10.3 mm vs 48.7 ± 10.9 mm, p = 0.040) and effective regurgitant orifice area (0.5 ± 0.4 cm 2 vs 0.3 ± 0.1 cm 2 ) were higher in patients undergoing surgery, compared to patients not undergoing surgery, respectively. The most common reason for not receiving surgery was that MR was not addressed by the treating physician and lost to clinical follow-up. Over 50% of patients that did not receive surgery had at least 1 indication based upon current practice guidelines.
Conclusions
In contemporary clinical practice, less than half of patients with moderate-severe and severe primary MR received surgery and many were not referred for surgical consultation.
Highlights
- •
Mitral regurgitation occurs in up to 10% of the general population.
- •
Less than 50% of patients with indications received treatment for mitral regurgitation.
- •
Predictors for referral to cardiothoracic surgery included age, presence of heart failure and history of hypertension.
- •
Many patients with severe mitral regurgitation are not referred for surgery despite indications for treatment. The reasons for non-referral require further study.
1
Introduction
Mitral regurgitation (MR) is a common valvular disorder that can lead to left ventricular (LV) enlargement and dysfunction and if untreated can cause congestive heart failure and death [ ]. Previous studies have shown that at least 10% of the general population and approximately 15% of patients over the age of 50 are affected by mitral valve disease [ ]. Thus, as life expectancy continues to increase, management of MR becomes more important.
Current practice guidelines recommend surgery for patients with chronic primary MR who meet specific criteria, while indications for intervention in secondary MR are less clear. Medical therapy has not been shown to significantly benefit patients or prevent LV dysfunction, thus is reserved for patients with high surgical risk or futility [ , ]. MitraClip device, a form of transcatheter mitral valve repair can be considered in patients with contraindications to surgery or high surgical risk [ ]. MitraClip has been shown to be safe and effective in reducing MR severity, improving reverse LV remodeling and improving symptoms at 1 year and is now recommended for non-surgical candidates with severe, symptomatic MR. [ , ] While there are clear recommendations for surgery in patients with severe primary MR, many patients do not receive appropriate referral and subsequent treatment [ , ]. Prior studies have shown that criteria for surgery are often under-recognized [ ].
The primary objective of this study was to evaluate the incidence of patients with severe MR evaluated at a tertiary medical center and determine the number of patients who receive appropriate referral and treatment. A secondary objective was to determine factors associated with these therapeutic decisions.
2
Methods
The transthoracic echocardiography database at Keck Medical Center of USC was searched from 2011 to 2016 to identify all patients with moderate-severe and severe MR. Primary MR was identified on the basis of abnormal mitral valve leaflets and secondary MR was identified in the setting of LV enlargement or LV dysfunction leading to impaired coaptation of functionally normal mitral leaflets. Patients with prior mitral valve surgery (mitral valve repair and replacement) were excluded.
Demographics, congestive heart failure symptoms, New York Heart Association (NYHA) functional class, laboratory values and pertinent echocardiographic measurements including ejection fraction (EF), effective regurgitant orifice area (EROA), pulmonary artery systolic pressure (PASP), LV end systolic diameter (LVESD) and LV end diastolic diameter (LVEDD) were collected. Society of Thoracic Surgery (STS) adult cardiac surgery risk was calculated using data at the time of the echocardiogram to assess operative risk [ ]. Eligibility for surgery was classified based upon American Heart Association/American College of Cardiology 2014 guidelines [ ]. Treatment recommendations were classified as referral to cardiology, referral to cardiothoracic surgery (CTS), receiving mitral valve surgery or receiving MitraClip. To categorize treatment recommendations, the following criteria were used: refused surgery – patient was offered surgery, but refused; MR not addressed – MR severity was not documented in the medical record following completion of the echocardiogram and the patient was not referred to Cardiology or CTS; medical therapy – medical therapy was documented as the treatment for MR; MR severity improved – repeat imaging showed MR improved to moderate or mild; high risk for surgery – patient was deemed to be high risk for surgery based upon the documentation during CTS consultation; did not meet criteria for surgery – based upon ACC/AHA guidelines from 2014, there was no indication for surgery; died prior to receiving treatment – the patient died prior to receiving treatment. The study was approved by the local institutional review board by waiver of consent given the retrospective nature of data collection.
Statistical analysis was performed using the SAS version 9.4 (SAS Institute, Inc.). Categorical variables are presented as numbers and percentages. Continuous variables are presented as mean ± standard deviation. Student t -test was used to compare categorical variables and chi-square or Fisher’s exact test to compare continuous variables. A p value <0.05 was considered statistically significant. A multivariate logistic regression model was used to evaluate univariate and multivariate factors associated with receiving CTS consultation or receiving surgery.
2
Methods
The transthoracic echocardiography database at Keck Medical Center of USC was searched from 2011 to 2016 to identify all patients with moderate-severe and severe MR. Primary MR was identified on the basis of abnormal mitral valve leaflets and secondary MR was identified in the setting of LV enlargement or LV dysfunction leading to impaired coaptation of functionally normal mitral leaflets. Patients with prior mitral valve surgery (mitral valve repair and replacement) were excluded.
Demographics, congestive heart failure symptoms, New York Heart Association (NYHA) functional class, laboratory values and pertinent echocardiographic measurements including ejection fraction (EF), effective regurgitant orifice area (EROA), pulmonary artery systolic pressure (PASP), LV end systolic diameter (LVESD) and LV end diastolic diameter (LVEDD) were collected. Society of Thoracic Surgery (STS) adult cardiac surgery risk was calculated using data at the time of the echocardiogram to assess operative risk [ ]. Eligibility for surgery was classified based upon American Heart Association/American College of Cardiology 2014 guidelines [ ]. Treatment recommendations were classified as referral to cardiology, referral to cardiothoracic surgery (CTS), receiving mitral valve surgery or receiving MitraClip. To categorize treatment recommendations, the following criteria were used: refused surgery – patient was offered surgery, but refused; MR not addressed – MR severity was not documented in the medical record following completion of the echocardiogram and the patient was not referred to Cardiology or CTS; medical therapy – medical therapy was documented as the treatment for MR; MR severity improved – repeat imaging showed MR improved to moderate or mild; high risk for surgery – patient was deemed to be high risk for surgery based upon the documentation during CTS consultation; did not meet criteria for surgery – based upon ACC/AHA guidelines from 2014, there was no indication for surgery; died prior to receiving treatment – the patient died prior to receiving treatment. The study was approved by the local institutional review board by waiver of consent given the retrospective nature of data collection.
Statistical analysis was performed using the SAS version 9.4 (SAS Institute, Inc.). Categorical variables are presented as numbers and percentages. Continuous variables are presented as mean ± standard deviation. Student t -test was used to compare categorical variables and chi-square or Fisher’s exact test to compare continuous variables. A p value <0.05 was considered statistically significant. A multivariate logistic regression model was used to evaluate univariate and multivariate factors associated with receiving CTS consultation or receiving surgery.
3
Results
Between 2011 and 2016, 1918 echocardiograms were reviewed and 412 patients with moderate-severe or severe MR were identified ( Fig. 1 ). Mean age was 67.8 ± 17.0 years (range 22 to 100 years), 2310 patients (56%) were male and there was a high prevalence of comorbid medical conditions ( Table 1 ). STS score was 8.0 ± 7.9, 166 patients (40%) had primary MR and 246 patients (60%) had secondary MR. Mean ejection fraction was 42.1 ± 19.3% and 155 patients (38%) had an ejection fraction <35%.
| Age, years | 67.8 ± 17.0 |
| Male | 230 (56%) |
| Coronary artery disease | 191 (46%) |
| Stroke | 61 (15%) |
| Hypertension | 256 (62%) |
| Diabetes mellitus | 133 (32%) |
| Obesity | 57 (14%) |
| Peripheral vascular disease | 32 (7.8%) |
| Chronic kidney disease | 78 (19%) |
| Malignancy | 59 (14%) |
| Associated valve disease | 155 (36%) |
| Pacemaker | 107 (26%) |
| Implantable cardiac defibrillator | 111 (27%) |
| Society of Thoracic Surgery score | 8.0 ± 7.9 |
| Etiology of mitral regurgitation | |
| Primary | 166 (40%) |
| Secondary | 246 (60%) |
| Ejection fraction, % | 42.1 ± 19.3 |
| Ejection fraction <35% | 155 (36%) |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
