Mitral regurgitation: a new clinical perspective

Mitral valve repair for posterior leaflet prolapse: Long-term comparison of loop implantation vs resection

BACKGROUND

Resection (triangular or quadrangular) is considered the gold standard for the treatment of posterior leaflet prolapse and loop implantation a more recent alternative. We aimed to compare the long-term outcomes of triangular or quadrangular resection vs loop implantation.

METHODS

Single-centre, retrospective analysis of mitral valve (MV) surgeries conducted from January 2005 to December 2015. Propensity score matching was based on seven key baseline variables.

RESULTS

Data from 721 patients were analyzed; 358 patients received loop implantation and 363 patients underwent resection. Patients had a mean age of 62 years, 33.0% were female and 50.6% had hypertension. Propensity score matching resulted in a matched group of 263 patients who received loop implantation or underwent resection, respectively. Postoperatively, the patients' mitral insufficiency was reduced from grade III/IV to either zero or trace (45.8%) or I (49.8%) and New York Heart Association class reduced from 66.9% in class III/IV preoperatively to 8.3% with no significant differences between groups. Fewer patients receiving loops had procedure-related complications. Fewer patients in the loop implantation group required permanent pacemaker implantation at 30 days (8.4% vs 2.3%; P = .002). The 10-year survival for patients in the resection (88.0%) and loop implantation (89.3%) groups had a hazard ratio of 1.224 (95% confidence interval, 0.633-2.367).

CONCLUSION

Our study showed that both loop implantation and resection were associated with comparable long-term survival in patients with posterior leaflet prolapse. Loop implantation is associated with a significantly higher rate of a successful repair, a significantly lower rate of MV replacement after repair failure, fewer procedure-related complications and better 30-day at comparable long-term outcomes.

Long-term outcomes of mitral regurgitation by type and severity

BACKGROUND

We aimed to determine the association of MR severity and type with all-cause death in a large, real-world, clinical setting.

METHODS

We reviewed full echocardiography studies at Duke Echocardiography Laboratory (01/01/1995-12/31/2010), classifying MR based on valve morphology, presence of coronary artery disease, and left ventricular size and function. Survival was compared among patients stratified by MR type and baseline severity.

RESULTS

Of 93,007 qualifying patients, 32,137 (34.6%) had ≥mild MR. A total of 8094 (8.7%) had moderate/severe MR, which was primary myxomatous (14.1%), primary non-myxomatous (6.2%), secondary non-ischemic (17.0%), and secondary ischemic (49.4%). At 10 years, patients with primary myxomatous MR or MR due to indeterminate cause had survival rates of >60%; primary non-myxomatous, secondary ischemic, and non-ischemic MR had survival rates <50%. While mild (HR 1.06, 95% CI 1.03-1.09), moderate (HR 1.31, 95% CI 1.27-1.37), and severe (HR 1.55, 95% CI 1.46-1.65) MR were independently associated with all-cause death, the relationship of increasing MR severity with mortality varied across MR types (P ≤ .001 for interaction); the highest risk associated with worsening severity was seen in primary myxomatous MR followed by secondary ischemic MR and primary non-myxomatous MR.

CONCLUSIONS

Although MR severity is independently associated with increased all-cause death risk for most forms of MR, the absolute mortality rates associated with worse MR severity are much higher for primary myxomatous, non-myxomatous, and secondary ischemic MR. The findings from this study support carefully defining MR by type and severity.

Mitral valve disease--current management and future challenges

The field of mitral valve disease diagnosis and management is rapidly changing. New understanding of disease pathology and progression, with improvements in and increased use of sophisticated imaging modalities, have led to early diagnosis and complex treatment. In primary mitral regurgitation, surgical repair is the standard of care. Treatment of asymptomatic patients with severe mitral regurgitation in valve reference centres, in which successful repair is more than 95% and surgical mortality is less than 1%, should be the expectation for the next 5 years. Transcatheter mitral valve repair with a MitraClip device is also producing good outcomes in patients with primary mitral regurgitation who are at high surgical risk. Findings from clinical trials of MitraClip versus surgery in patients of intermediate surgical risk are expected to be initiated in the next few years. In patients with secondary mitral regurgitation, mainly a disease of the left ventricle, the vision for the next 5 years is not nearly as clear. Outcomes from ongoing clinical trials will greatly inform this field. Use of transcatheter techniques, both repair and replacement, is expected to substantially expand. Mitral annular calcification is an increasing problem in elderly people, causing both mitral stenosis and regurgitation which are difficult to treat. There is anecdotal experience with use of transcatheter valves by either a catheter-based approach or as a hybrid technique with open surgery, which is being studied in early feasibility trials.

Thoracic epidural anesthesia improves early outcome in patients undergoing cardiac surgery for mitral regurgitation: a propensity-matched study

OBJECTIVE

There are no large studies that investigate the effect of thoracic epidural anesthesia (TEA) combined with general anesthesia (GA) in patients undergoing valvular surgery. The authors hypothesized that TEA might improve clinically relevant endpoints in patients with primary mitral regurgitation.

DESIGN

Propensity-matched study.

SETTING

Cardiac surgery.

PARTICIPANTS

Patients scheduled for mitral valve repair or replacement were studied.

INTERVENTIONS

A propensity model was constructed to match 33 patients receiving TEA combined with GA with 33 patients receiving standard GA alone.

MEASUREMENTS AND MAIN RESULTS

Overall, the TEA group suffered fewer adverse events than the GA group: 10 (30%) v 23 (10%) with p = 0.002. In particular, the TEA group had a lower incidence of pulmonary events, 6 (18%) v 15 (45%) with p = 0.02, and of cardiac events, 8 (24%) v 16 (49%) with p = 0.04. Median (interquartile) time on mechanical ventilation was reduced in the TEA group, 11 (9-15) v 17 (12-36) with p = 0.007.

CONCLUSIONS

This propensity-matched study suggested that TEA might be advantageous in patients undergoing surgery for mitral regurgitation.

Midterm results of mitral valve repair: closed versus open annuloplasty ring

BACKGROUND

Closed and open annuloplasty rings are both used for mitral valve repair. This study compared the clinical and echocardiographic results in patients with degenerative mitral disease undergoing MV repair with closed semirigid rings vs open bands.

METHODS

Between 2004 and 2008, 377 patients (mean age, 59 + or - 12 years) underwent mitral valve repair. Valve pathology was degenerative in 273 (72%). Closed rings were used in 163 (60%) and open rings in 110 (40%). Patients had similar characteristics and comorbidities. In addition to annuloplasty, repair techniques included leaflet resection (48% and 77%, p < 0.01), artificial chordal (55% and 36%, p < 0.01), and edge-to-edge repair (4% and 4%, p = 0.79), in closed and open groups, respectively.

RESULTS

One patient in each group died (0.7%). Mean follow-up was 19 + or - 14 (closed group) and 34 + or - 15 months (open group; p < 0.01). Freedom from reoperation was 97.5% (closed group) vs 96.5% (open group). At follow-up, New York Heart Association functional class was similar between groups, and 91% in the closed group and 84% in the open group were free from moderate or severe mitral regurgitation (p = 0.05). Closed group patients had a longer line of leaflet coaptation (9.1 + or - 2.7 mm) vs the open group (7.1 + or - 1.9 mm; p < 0.01).

CONCLUSIONS

Patients with closed semirigid annuloplasty rings demonstrated significantly longer lines of leaflet coaptation and tendency toward better echocardiographic midterm results than patients with open bands and may, therefore, benefit from improved repair durability.

Mitral valve annuloplasty and myocardial revascularization in the treatment of ischemic dilated cardiomyopathy

The aim of this study was to examine perioperative mortality and morbidity and midterm results in patients undergoing coronary bypass graft and mitral valve annuloplasty with advanced dilated cardiomyopathy. Sixty-one patients with ischemic dilated cardiomyopathy underwent coronary artery bypass grafting and mitral valve annuloplasty between January 1998 and December 2003. Patients eligible for revascularization that presented a mild or more severe mitral valve regurgitation at echocardiography (effective regurgitant orifice > 0.2 cm(2)) were considered for annuloplasty with a Cosgrove ring. New York Heart Association class (NYHA) III/IV was present in 40 patients (66%) and Canadian Cardiovascular Society class III-IV in 19 (31%). A previous acute myocardial infarction was reported in 48 patients (79%). The mean number of graft anastomoses was 2.5 +/- 0.7 and the left internal mammary artery was used in 49 patients (80%). In-hospital mortality was 4.9% (3 patients), due to unsuccessful weaning from cardiopulmonary bypass, multiple organ failure, and stroke, respectively. Left ventricle ejection fraction improved from 28.9% +/- 5.2% preoperatively to 35.4% +/- 8.1% at follow-up (P = 0.0001) and a significant reduction in NYHA III/IV was detected: from 40 patients preoperatively (66%) to 14 (31%) at follow-up (P = 0.031). Midterm cardiac-related mortality rate was 3.4%. In our experience combined coronary artery bypass grafting and ring annuloplasty for ischemic dilated cardiomyopathy can be performed with acceptable risks for in-hospital mortality and morbidity. Midterm results show a good survival rate and a durable functional improvement in this subset of patients.

Mitral regurgitation: determinants of referral for cardiac surgery by Canadian cardiologists

PURPOSE

Advances in surgery permit for earlier intervention with improved outcomes for patients with mitral regurgitation (MR). Many patients still appear to be referred to surgery late in their course. Consensus guidelines were compared with the surgical referral practices for MR among Canadian cardiologists.

METHODS

A self-administered questionnaire was mailed to all adult cardiologists in Canada. This included seven case scenarios, as well as direct questions designed to establish the influence of factors including atrial fibrillation, pulmonary hypertension, left ventricular (LV) dilation, experience of the cardiac surgeon, symptoms and ejection fraction (EF) on referral.

RESULTS

There were 319 respondents; LVEF was rated as extremely important in 71.5% of patients and moderately important in 26% of patients. In asymptomatic patients, EF of 50% to 60% was correctly identified as a trigger for surgery by 57.2 % of cardiologists, while only 15.6% of cardiologists correctly referred New York Heart Association class II patients with normal LV function. The group complied in only 4.77 of the seven case scenarios. Compliance was inversely related to years in practice for asymptomatic patients with mild LV dysfunction, as well as in overall compliance. Referral practices were similar among clinicians, echocardiographers, interventional cardiologists and researchers, with no differences in geographic region or academic affiliation.

CONCLUSION

Compliance with published guidelines for patients with MR and either New York Heart Association class II or mild LV dysfunction among Canadian cardiologists was poor. Compliance was somewhat better in more recent graduates, suggesting the need to institute programs geared at enhancing knowledge of published standards and introduce practical tools to aid in their implementation.

Quantitative determinants of the outcome of asymptomatic mitral regurgitation

BACKGROUND

The clinical outcome of asymptomatic mitral regurgitation is poorly defined, and the treatment is uncertain. We studied the effect on the outcome of quantifying mitral regurgitation according to recent guidelines.

METHODS

We prospectively enrolled 456 patients (mean [+/-SD] age, 63+/-14 years; 63 percent men; ejection fraction, 70+/-8 percent) with asymptomatic organic mitral regurgitation, quantified according to current recommendations (regurgitant volume, 66+/-40 ml per beat; effective regurgitant orifice, 40+/-27 mm2).

RESULTS

The estimated five-year rates (+/-SE) of death from any cause, death from cardiac causes, and cardiac events (death from cardiac causes, heart failure, or new atrial fibrillation) with medical management were 22+/-3 percent, 14+/-3 percent, and 33+/-3 percent, respectively. Independent determinants of survival were increasing age, the presence of diabetes, and increasing effective regurgitant orifice (adjusted risk ratio per 10-mm2 increment, 1.18; 95 percent confidence interval, 1.06 to 1.30; P<0.01), the predictive power of which superseded all other qualitative and quantitative measures of regurgitation. Patients with an effective regurgitant orifice of at least 40 mm2 had a five-year survival rate that was lower than expected on the basis of U.S. Census data (58+/-9 percent vs. 78 percent, P=0.03). As compared with patients with a regurgitant orifice of less than 20 mm2, those with an orifice of at least 40 mm2 had an increased risk of death from any cause (adjusted risk ratio, 2.90; 95 percent confidence interval, 1.33 to 6.32; P<0.01), death from cardiac causes (adjusted risk ratio, 5.21; 95 percent confidence interval, 1.98 to 14.40; P<0.01), and cardiac events (adjusted risk ratio, 5.66; 95 percent confidence interval, 3.07 to 10.56; P<0.01). Cardiac surgery was ultimately performed in 232 patients and was independently associated with improved survival (adjusted risk ratio, 0.28; 95 percent confidence interval, 0.14 to 0.55; P<0.01).

CONCLUSIONS

Quantitative grading of mitral regurgitation is a powerful predictor of the clinical outcome of asymptomatic mitral regurgitation. Patients with an effective regurgitant orifice of at least 40 mm2 should promptly be considered for cardiac surgery.

Changes in systemic sympathetic nervous system activity after mitral valve surgery and their relationship to changes in left ventricular size and systolic performance in patients with mitral regurgitation

BACKGROUND

We have shown that the systemic sympathetic nervous system (SNS) is activated in patients with chronic mitral regurgitation (MR). However, the fate of systemic SNS activity after surgical correction of MR is currently unknown.

METHODS

We examined 14 patients with MR who had normal sinus rhythm with an investigational, preoperative cardiac catheterization, including arterial norepinephrine (NE) sampling and [(3)H]-NE infusions and arterial blood sampling to determine NE kinetic parameters using a 2-compartment modeling analysis. The arterial NE and NE kinetic parameters were determined in all patients after mitral valve surgery (MVS) at a mean of 12 months. A 2-dimensional echocardiographic examination was also performed before and after MVS.

RESULTS

The average extravascular NE release rates (NE(2)) before and after MVS were 1.89 +/- 0.66 and 2.26 +/- 0.82 microg/min/m(2) (P =.24), respectively. The average left ventricular (LV) end-diastolic dimension, fractional shortening, and ejection fraction decreased, whereas the mean LV end-systolic dimension did not change between the pre- and post-MVS echocardiographic studies. However, these group averages were comprised of patients with MR in whom the NE(2) and echocardiographic values both increased and decreased. This lack of homogeneity was a reflection of our new observation that the pre- to post-MVS changes in NE(2) were directly proportional to the changes in LV end-systolic dimension (r = 0.91, P <.001) and inversely related to the changes in LV fractional shortening (r = -0.82, P <.001) and ejection fraction (r = -0.78, P <.001).

CONCLUSIONS

The response in systemic SNS activity in patients with MR after MVS is not homogeneous, and these changes are concordant with the post-MVS changes in LV size and systolic performance. These data further support our earlier observations and extend them to suggest that systemic SNS activation in patients with chronic MR is related to LV remodeling and impaired systolic performance.

Late outcome of mitral valve surgery for patients with coronary artery disease

BACKGROUND

We plan to determine whether the cause of mitral valve regurgitation, ischemic or degenerative, affects survival after combined mitral valve repair or replacement and coronary artery bypass grafting (CABG) surgery and to assess the influence of residual mitral regurgitation on late outcome.

METHODS

A retrospective study was made of 302 patients having mitral valve repair or replacement and CABG from January 1987 through December 1996. Risk factors for death, for development of New York Heart Association class III or IV congestive heart failure (CHF), and recurrent mitral valve regurgitation were identified by proportional hazards analysis.

RESULTS

The cause of mitral regurgitation was ischemic in 137 patients (45%) and degenerative in 165 patients (55%). Valve replacement was performed in 51 patients (17%) and valve repair in 251 patients (83%). Median follow-up was 64 months. Ten-year actuarial survival rates were 33% (95% confidence interval: 22% to 47%) in the ischemic group and 52% (95% confidence interval: 42% to 64%) in the degenerative group. Univariate predictors of death, were entered into a multivariate model. Older age, ejection fraction of 35% or less, three-vessel coronary artery disease, replacement of the mitral valve, and residual mitral regurgitation at dismissal were independent risk factors for death. The cause of mitral valve regurgitation (ischemic or degenerative) was not an independent predictor of long-term survival, class III or IV CHF, or recurrent regurgitation.

CONCLUSIONS

Survival after mitral valve surgery and CABG is determined by the extent of coronary disease and ventricular dysfunction and by the success of the valve procedure; etiology of mitral valve regurgitation has relatively little impact on late outcome.

Prophylactic mitral reconstruction for mitral regurgitation

BACKGROUND

Mitral regurgitation (MR) will produce myocardial dysfunction. The goal of this study was to review outcomes of mitral valve reconstruction in asymptomatic patients with severe MR.

METHODS

From 1992 to 2000, 93 asymptomatic patients with degenerative disease and severe MR underwent mitral valve reconstruction. Mean preoperative left ventricular internal diameter diastole was 56 +/- 8 mm and ejection fraction was 60% +/- 6%. Mean age was 47 +/- 10 years and mean follow-up 23 +/- 27 months. All patients underwent complex reconstruction.

RESULTS

There were no deaths and two late reoperations. One was for systolic anterior motion of the anterior leaflet of the mitral valve requiring valve replacement and one for hemolysis requiring re-repair. There was one perioperative transient ischemic attack and no late thromboembolic events. At follow-up all but 1 patient remains in NYHA class I and all had no MR except in 2 patients at 63 and 89 months.

CONCLUSIONS

Mitral valve reconstruction for "asymptomatic" MR can be performed with no mortality and low morbidity before development of left ventricular dysfunction. Early prophylactic repair is advocated in the presence of severe MR if valve reparability is assured.

Minimally invasive versus sternotomy approaches for mitral reconstruction: comparison of intermediate-term results

BACKGROUND

This study compares intermediate-term outcomes of mitral valve reconstruction after either the standard sternotomy approach or the new minimally invasive approach. Although minimally invasive mitral valve operations appear to offer certain advantages, such as reduced postoperative discomfort and decreased postoperative recovery time, the intermediate-term functional and echocardiographic efficacy has not yet been documented.

METHODS

From May 1996 to February 1999, 100 consecutive patients underwent primary mitral reconstruction through a minimally invasive right anterior thoracotomy and peripheral cardiopulmonary bypass and Port-Access technology (Heartport, Inc, Redwood City, Calif). Outcomes were compared with those for our previous 100 patients undergoing primary mitral repair who were operated on with the standard sternotomy approach.

RESULTS

Although patients were similar in age, the patients undergoing the minimally invasive approach had a lower preoperative New York Heart Association classification (2.1 +/- 0.5 vs 2.6 +/- 0.6, P <.001). There was one (1.0%) hospital mortality with the sternotomy approach and no such case with the minimally invasive approach. Follow-up revealed that residual mitral insufficiency was similar between the minimally invasive and sternotomy approaches (0.79 +/- 0.06 vs 0.77 +/- 0.06, P =.89, 0- to 3-point scale); likewise, the cumulative freedom from reoperation was not significantly different (94.4% vs 96.8%, P =.38). Follow-up New York Heart Association functional class was significantly better in the patients undergoing the minimally invasive approach (1.5 +/- 0.05 vs 1.2 +/- 0.05, P <.01).

CONCLUSIONS

These findings demonstrate comparable 1-year follow-up results after minimally invasive mitral valve reconstruction. Both echocardiographic results and New York Heart Association functional improvements were compatible with results achieved with the standard sternotomy approach. The minimally invasive approach for mitral valve reconstruction provides equally durable results with marked advantages for the patient and should be more widely adopted.

Relation of systemic sympathetic nervous system activation to echocardiographic left ventricular size and performance and its implications in patients with mitral regurgitation

We have previously demonstrated that the systemic sympathetic nervous system (SNS) is activated in proportion to an increase in cineventriculographic left ventricular (LV) end-systolic volume and decrease in ejection fraction (EF) in patients with chronic mitral regurgitation (MR). However, the relation between noninvasive echocardiographic measures of LV size and performance and systemic SNS activation and their clinical implications in patients with MR is not known. We studied 17 MR patients with echocardiography, arterial norepinephrine (NE) sampling, and [3H]-NE infusions and arterial blood sampling to determine NE kinetic parameters using a 2-compartment analysis, including extravascular NE release rates (NE2, index of SNS activity) and the metabolic clearance rate from the vascular compartment. The arterial NE values correlated with LV end-systolic dimensions (r = 0.50, p = 0.04), but not with LV end-diastolic dimensions, and EF or fractional shortening measures. The NE2 values correlated with LV end-systolic dimensions (r = 0.53, p = 0.03) and inversely with LVEF (r = -0.45, p = 0.07) and fractional shortening (r = 0.43, p = 0.08) measures, but not with LV end-diastolic dimensions. The metabolic clearance rate values showed an inverse correlation with LV end-diastolic (r = -0.52, p = 0.03) and end-systolic (r = -0.49, p = 0.04) dimensions, but not with LV performance measures. The increase in NE2 values was progressive as the LV endsystolic dimensions increased and more marked at LV end-systolic dimensions > or = 40 mm. Thus, activation of the SNS is related to an increase in echocardiographic LV end-systolic dimensions and a decrease in LV performance measures in chronic MR. Medica, Inc.

Elevated circulating levels of serum tumor necrosis factor-alpha in patients with hemodynamically significant pressure and volume overload

OBJECTIVES

We sought to determine whether serum tumor necrosis factor-alpha (TNF-alpha) levels are elevated in patients with hemodynamically significant pressure and volume overload.

BACKGROUND

It has been previously shown that TNF-alpha messenger ribonucleic acid (mRNA) and protein are rapidly expressed in the hearts of animal models subjected to abrupt hemodynamic overloading. The clinical significance of these experimental findings has not been tested in pathophysiologically relevant clinical models in human subjects.

METHODS

We prospectively measured serum TNF-alpha levels and serum TNF receptor 1 and 2 levels in 21 patients with severe aortic stenosis (AS), in 26 patients with 3+ to 4+ mitral regurgitation (MR) and in normal age- and gender-matched control subjects. Patients with AS and MR were either in New York Heart Association (NYHA) functional class I or II and had no significant coronary disease. We compared the cytokine levels among the groups using analysis of variance. We related cytokine levels to the severity of AS using simple regression analysis.

RESULTS

Serum TNF-alpha levels in patients with AS (2.1 +/- 1.6 pg/ml, n = 21) and MR (1.3 +/-0.7 pg/ml, n = 26) were significantly higher than those in the control subjects (0.7 +/-0.2 pg/ml, n = 28). Serum TNF receptor 1 and 2 levels were also higher in patients with AS and MR than in control subjects. Cytokine levels were higher in patients in NYHA class II than in those in class I. In patients with a normal ejection fraction (>50%, n = 16), there was a mild positive correlation (r = 0.56, p = 0.025) between serum TNF-alpha levels and the mean gradient across the aortic valve.

CONCLUSIONS

This study demonstrates that serum TNF-alpha is elevated in patients with chronic hemodynamic overloading and early cardiac decompensation. Furthermore, these findings suggest not only that peripheral TNF-alpha levels correlate with the severity of the hemodynamic pressure overload, but also that peripheral TNF-alpha and TNF receptor levels increase in direct relation to deteriorating NYHA functional class.

Repair of anterior leaflet mitral valve prolapse: chordal replacement versus chordal shortening

BACKGROUND

To determine the optimal method of repair for severe, segmental anterior leaflet prolapse, we analyzed outcome of 121 patients who underwent chordal shortening (n = 46) and chordal replacement (n = 75) from 1988 to 1996.

METHODS

Chordae were replaced with expanded polytetrafluoroethylene sutures. Patients had an annuloplasty with either chordal replacement or shortening. Follow-up was 100% complete (mean, 3.7 years).

RESULTS

Mean age was 62.1 years, 86 were men, and 60 patients had isolated valve repair. There was one hospital death and 14 late deaths for a 5-year actuarial survival of 86.4%+/-4.5%. Sixteen patients underwent reoperation, 5 in the replacement group and 11 in the shortening group. Mechanism of valve failure in the replacement group was native chordae rupture (n = 4) and neochordae dehiscence (n = 1). With chordal shortening, repair failure was attributed to rupture of shortened chordae (n = 8), leaflet prolapse with and without annuloplasty ring dehiscence (n = 2), and native chordae elongation (n = 1). Risk of reoperation because of repair failure at 3.5 years was 1.4% in the chordal replacement group and 14.8% in the chordal shortening group (p = 0.02).

CONCLUSIONS

Chordal replacement is superior to chordal shortening, providing a predictable method for correction of mitral regurgitation with a low incidence of reoperation.

Staphylococcus lugdunensis endocarditis: a complication of vasectomy?

Three cases of Staphylococcus lugdunensis endocarditis have been reported in patients with a history of vasectomy preceding the development of endocarditis. We describe a new case of a 39-year-old man who developed infective endocarditis due to S. lugdunensis after vasectomy. He was successfully treated with a 7-week course of intravenous antibiotics and subsequently underwent mitral valve reconstruction for severe mitral regurgitation. The present case further supports an association between vasectomy and S. lugdunensis endocarditis.