Coronary Microvascular Dysfunction as a Mechanism of Angina in Severe AS: Prospective Adenosine-Stress CMR Study

BACKGROUND

Although a common symptom in patients with severe aortic stenosis (AS) without obstructive coronary artery disease (CAD), little is known about the pathogenesis of exertional angina.

OBJECTIVES

This study sought to prove that microvascular dysfunction is responsible for chest pain in patients with severe AS and normal epicardial coronary arteries using adenosine-stress cardiac magnetic resonance (CMR) imaging.

METHODS

Between June 2012 and April 2015, 117 patients with severe AS without obstructive CAD and 20 normal controls were enrolled prospectively. After exclusions, study patients were divided into 2 groups according to presence of exertional chest pain: an angina group (n = 43) and an asymptomatic group (n = 41), and the semiquantitative myocardial perfusion reserve index (MPRI) was calculated.

RESULTS

MPRI values were significantly lower in severe AS patients than in normal controls (0.90 ± 0.31 vs. 1.25 ± 0.21; p < 0.001), and were much lower in the angina group than the asymptomatic group (0.74 ± 0.25 vs. 1.08 ± 0.28; p < 0.001). In logistic regression analysis, the only independent predictor for angina was MPRI (odds ratio: 0.003; p < 0.001). Univariate associations with MPRI were identified for diastolic blood pressure, E/e' ratio, left ventricular volume and ejection fraction, cardiac index, presence of late gadolinium enhancement, and left ventricular mass index (LVMI). In multivariate analysis, LVMI was the strongest contributing factor to MPRI (standardization coefficient: -0.428; p < 0.001).

CONCLUSIONS

Our results suggest that, in patients with severe AS without obstructive CAD, angina is related to impaired coronary microvascular function along with LV hypertrophy detectable by semiquantitative MPRI using adenosine-stress CMR.

CLINICAL TRIAL REGISTRATION

NCT02575768.

Optimal Timing of Venoarterial-Extracorporeal Membrane Oxygenation in Acute Myocardial Infarction Patients Suffering From Refractory Cardiogenic Shock

BACKGROUND

Although there is an increase in the use of mechanical circulatory support devices to rescue patients with acute myocardial infarction (AMI) complicated by refractory cardiogenic shock (CS), the optimal timing of the application remains controversial. Therefore, this study aimed to compare the clinical outcomes between venoarterial-extracorporeal membrane oxygenation (VA-ECMO) insertion before and after coronary revascularization in AMI patients with refractory CS.

METHODS AND RESULTS

A total of 253 patients with AMI who underwent revascularization therapy with VA-ECMO were included. The study population was stratified into extracorporeal cardiopulmonary resuscitation (E-CPR) before revascularization (N=106, reference cohort) and refractory CS without E-CPR before revascularization (n=147, comparison cohort). Patients with refractory CS but without E-CPR before revascularization were further divided into VA-ECMO before revascularization (N=50) and VA-ECMO after revascularization (n=97). The primary endpoint was a composite of in-hospital mortality, left ventricular assist device implantation, and heart transplantation. The primary endpoint occurred in 60 patients (40.8%) of the comparison cohort and 51 patients (48.1%) of the reference cohort. Among the comparison cohort, the primary endpoint was significantly lower in VA-ECMO before revascularization than in VA-ECMO after revascularization (32.0% vs. 49.5%, OR 0.480, 95% CI 0.235-0.982, P=0.045). A similar trend was observed after a 1-year follow up.

CONCLUSIONS

Early initiation of VA-ECMO before revascularization therapy might improve clinical outcomes in patients with AMI complicated by refractory CS.

Long-term outcomes of drug-eluting stent implantation versus coronary artery bypass grafting for patients with coronary artery disease and chronic left ventricular systolic dysfunction

Limited data are available on comparing the clinical outcomes of coronary artery bypass grafting (CABG) and drug-eluting stent (DES) implantation in patients with reduced left ventricular systolic function in the DES era. From January 2003 to December 2010, 953 patients with reduced left ventricular systolic function, defined as a left ventricular ejection fraction <50%, who had undergone percutaneous coronary intervention with DESs (n = 402) or CABG (n = 551) were enrolled in a retrospective, observational registry. Patients with acute myocardial infarction were excluded. Propensity score-matching analysis was also performed in 141 patient pairs. The primary outcome was all-cause death. The median follow-up duration was 32 months (interquartile range 15 to 61). All-cause death occurred in 81 patients (20.1%) in the DES group and 98 patient (17.8%) in the CABG group (p = 0.524). After propensity score matching, the long-term cumulative rate of death was not significantly different between the 2 groups (DES vs CABG 21.3% vs 19.1%; adjusted hazard ratio 1.23, 95% confidence interval 0.57 to 2.66, p = 0.603). However, the rate of major adverse cardiac and cerebrovascular events (35.5% vs 24.1%, adjusted hazard ratio 1.69, 95% confidence interval 1.04 to 2.77, p = 0.036) was higher in the DES group than the CABG group. This was driven by the higher incidence of repeat revascularization in the DES group (11.3% vs 4.3%, adjusted hazard ratio 3.65, 95% confidence interval 1.01 to 10.37, p = 0.018). In conclusion, DES implantation provides comparable long-term clinical outcomes, except for repeat revascularization, to CABG in patients with coronary artery disease and chronic left ventricular systolic dysfunction.

Tricuspid annuloplasty using the MC3 ring for functional tricuspid regurgitation

BACKGROUND

A recently introduced tricuspid annuloplasty ring, the MC(3) ring, has a 3-dimensional form that is designed to remodel the tricuspid valve annulus. The aim of this study was to investigate its clinical performance.

METHODS AND RESULTS

From December 2004 to April 2008, 103 patients underwent tricuspid annuloplasty using the MC(3) ring (mean age, 52+/-13 years; 63.6% women). The average preoperative tricuspid regurgitation (TR) grade was 2.5+/-0.8, and the mean preoperative systolic pulmonary artery pressure was 48.4+/-15.0 (24-88) mmHg; the mean follow-up was 26.7+/-11.2 (0-52) months. One patient died after surgery (1.0%), because of cor pulmonale. No MC(3) ring-related complications, such as, atrioventricular block, ring dehiscence or thromboembolism, were encountered. Predischarge echocardiography showed a significant decrease in the TR grade (2.5+/-0.8 to 0.8+/-0.8, respectively; P<0.001). After a median 15 months, the mean TR grade was stable (0.9+/-0.8). The mean systolic pulmonary artery pressure was also lower than its preoperative value (33.9+/-7.9 vs 48.4+/-15.0 mmHg, respectively; P<0.001).

CONCLUSIONS

The MC(3) ring provides good mid-term clinical and echocardiographic results for TR. However, long-term follow-up is mandatory to confirm the stability of this procedure.

Management of acute massive pulmonary embolism: Is surgical embolectomy inferior to thrombolysis?

BACKGROUND

Although current guidelines for pulmonary embolism (PE) treatment recommend surgical embolectomy when thrombolysis is contraindicated or has failed, their clinical outcomes rarely have been compared directly.

METHODS

After excluding patients aged under 18 years and those with submassive or non-massive PE, 45 consecutive patients (median age, 68 years; 62% female; 31% experienced cardiac arrest before PE treatment onset; 33% had cancer diagnosis history; and 29% received extracorporeal membrane oxygenation [ECMO]) who underwent only thrombolysis (TL group; n=19) or surgical embolectomy (SE group; n=26, including 4 who had failed thrombolysis) for acute massive PE from 2000 to 2013 at Samsung Medical Center were enrolled to assess cardiac mortality as primary outcome.

RESULTS

Median follow-up duration was 17.2 months. In the SE group, significantly higher proportions of patients had recent surgery and ECMO. Overall 30-day all-cause mortality rate was 24% (n=11), without significant difference between the SE (15%) and TL (37%) groups (P=0.098); however, cardiac mortality rate was significantly higher in the TL than SE group (Log rank P=0.023). TL was an independent multivariate predictor of cardiac death (P=0.03).

CONCLUSION

In this small retrospective single center experience, surgical embolectomy is associated with lower cardiac mortality risk than thrombolysis, which might render it first-line treatment option for acute massive PE for patients without life-limiting comorbidities.

Predicting Left Ventricular Dysfunction after Surgery in Patients with Chronic Mitral Regurgitation: Assessment of Myocardial Deformation by 2-Dimensional Multilayer Speckle Tracking Echocardiography

Background and Objectives

The development of postoperative left ventricular (LV) dysfunction is a frequent complication in patients with chronic severe mitral valve regurgitation (MR) and portends a poor prognosis. Assessment of myocardial deformation enables myocardial contractility to be accurately estimated. The aim of the present study was to evaluate the predictive value of preoperative regional LV contractile function assessment using two-dimensional multilayer speckle-tracking echocardiography (2D MSTE) analysis in patients with chronic severe MR with preserved LV systolic function.

Subjects and Methods

Forty-three consecutive patients with chronic severe MR with preserved LV systolic function scheduled for mitral valve replacement (MVR) or MV repair were prospectively enrolled. Serial echocardiographic studies were performed before surgery, at 7 days follow-up, and at least 3 months follow-up postoperatively. The conventional echocardiographic parameters were analyzed. Global longitudinal strain (GLS) was obtained quantitatively by 2D MSTE.

Results

The mean age of patients was 51.7±14.3 years and 25 (58.1%) were male. In receiver-operating characteristic curve analysis, the most useful cutoff value for discriminating postoperative LV remodeling in severe MR with normal LV systolic function was -20.5% of 2D mid-layer GLS. Patients were divided into two groups by the baseline GLS -20.5%. Preoperative GLS values strongly predicted postoperative LV remodeling or LV dysfunction. The postoperative degree of decrease in LV end-diastolic dimension might be an additive predictive factor.

Conclusion

STE can be used to predict a decrease in LV function after MVR in patients with chronic severe MR. This promising method could be of use in the clinic when trying to decide upon the optimum time to schedule surgery for such patients.

Long-term results of the leaflet extension technique in aortic regurgitation: thirteen years of experience in a single center

BACKGROUND

We evaluated the effectiveness and durability of the leaflet extension technique for correction of aortic regurgitation (AR) and the long-term clinical results.

METHODS

Between March 1995 and August 2004, 41 consecutive patients were included. The mean age was 32.2 +/- 13.9 years. The causes of AR were rheumatic in 31 patients (75.5%), degenerative in 2 patients (4.9%), bicuspid aortic valve in 4 patients (9.8%), infective endocarditis in 1 patient (2.4%), and congenital in 3 patients (7.3%). Leaflet extensions were performed in three leaflets for 32 patients, two leaflets for 3 patients, and only one leaflet for 6 patients. The mean follow-up duration was 92.9 +/- 48.4 months.

RESULTS

There were no early deaths and 2 late deaths. One patient died of cancer and the other patient died of infective endocarditis. The cardiac-related mortality was 2.4% (1 of 41 patients). During a mean follow-up of 7 years, severe AR was detected in 1 patient and moderate AR in 6 patients (17.0%; 7 of 41 patients). The causes of recurrent AR were infective endocarditis in 3 patients, disease progression in 3 patients, and Behçet's diseases in 1 patient. We performed 6 reoperations (14.6%), 3 in patients owing to infective endocarditis, 2 in patients owing to disease progression, and 1 in a patient owing to the suture dehiscence associated with Behçet's disease. The cumulative survival was 92.6% at 13 years. Freedom from recurrent AR was 97.5% at 5 years, 81.7% at 10 years, and 68.1% at 13 years.

CONCLUSIONS

The long-term durability of the leaflet extension technique was acceptable. The reoperations increased with time, but pericardial leaflet dysfunction was not the cause.

Tricuspid Valve Replacement vs. Repair in Severe Tricuspid Regurgitation

BACKGROUND

The aim of this study was to compare early and late outcomes of tricuspid valve replacement (TVR) and tricuspid valve repair (TVr) for severe tricuspid regurgitation (TR).

METHODS AND RESULTS

From 1994 to 2012, 360 patients (mean age, 58±13 years) with severe TR underwent TVR (n=97, 27%) or TVr (n=263, 73%). Among them, 282 patients (78%) had initial rheumatic etiology, and 307 patients (85%) had preoperative atrial fibrillation. The TVR group had higher total bilirubin, higher baseline central venous pressure, and higher incidence of previous cardiac operation. There was no difference in early mortality (TVR:TVr, 3.1%:3.4%, P=0.877). Ten-year overall survival (TVR:TVr, 72%:70%, P=0.532) and 10-year freedom from cardiac death (TVR:TVr, 76%:77%, P=0.715) were not significantly different between groups. After applying stabilized inverse probability of treatment weighting methods, there were still no significant differences in early mortality (P=0.293), overall survival (P=0.649) or freedom from cardiac death (P=0.870). Higher NYHA functional class, total bilirubin (>2 mg/dL), initial central venous pressure, and cardiopulmonary bypass time were independent predictors of early mortality. Older age, LV dysfunction (EF <40%), and hemoglobin <10 g/dL were independent predictors of late cardiac mortality.

CONCLUSIONS

Compared with TVr, TVR had acceptable early and late outcomes in patients with severe TR. TVR can be considered as a valid option with acceptable clinical outcomes in patients who are not suitable candidates for TVr.

Long-term results of radical pericardiectomy for constrictive pericarditis in Korean population

Background

The extent of pericardiectomy is an important issue in constrictive pericarditis but its impact on long-term outcomes has been rarely reported. We compared long-term results of radical pericardiectomy with conventional phrenic to phrenic pericardiectomy.

Methods

Ninety patients who underwent pericardiectomies between February 1995 and April 2015 were reviewed retrospectively. They were classified into conventional (n = 37) and radical (n = 53) groups according to pericardiectomy being performed anterior or posterior to the phrenic nerves, respectively. The follow-up duration at outpatient clinic was 37.6 (11.7, 86.6) months and the survival data until 91.6 (54.5, 147.0) months were obtained. The last echocardiographies were done at 22.4 (4.35, 60.85) months.

Results

The early mortality rate was 4.4% (4/90). They all belonged to the conventional group and died of low cardiac output syndrome. The survival rate was higher in the radical group (P = .032, 74.7 ± 9.2% versus 50.4 ± 11.9% in 20 years). NYHA class of both groups had recovered until the last follow-up but the radical group showed better recovery (P < .001). The conventional pericardiectomy (HR = 6.181; 95% CI (1.042, 36.656)), redosternotomy (HR = 6.441; 95% CI (1.224, 33.889) and preoperative grade of tricuspid regurgitation (HR = 15.003; 95% CI (1.099, 204.894) were associated with late mortality. Right ventricular systolic pressure decreased, and pericardial thickening resolved only in the radical group with significant intergroup differences as time went on. Tricuspid regurgitation worsened after the operation in both groups, but it deteriorated more in the conventional group. However, it improved over time in the radical group.

Conclusions

Radical pericardiectomy led to greater improvement in right ventricular systolic pressure and lesser deterioration of tricuspid regurgitation with the passage of time than did the conventional procedure. Conventional pericardiectomy and preoperative higher grade tricuspid regurgitation were associated with long-term mortality.

Electronic supplementary material

The online version of this article (10.1186/s13019-019-0845-7) contains supplementary material, which is available to authorized users.

Influence of vein graft use on postoperative 1-year results after off-pump coronary artery bypass surgery

OBJECTIVE

We studied the postoperative 1-year results after off-pump coronary artery bypass surgery (OPCAB) with one or more saphenous vein grafts.

METHODS

We compared the clinical and angiographic results of 833 patients who underwent OPCAB between 1998 and 2004. Group 1 patients (n=135) received one or more vein grafts. Group 2 patients (n=698) received total arterial grafts. Coronary angiographies were performed early postoperatively (n=804, 1.6+/-1.5 days), and 1 year postoperatively (n=671, 12.1+/-4.2 months).

RESULTS

There were no significant differences in patient characteristics, operative mortalities, and morbidities between the two groups (p=ns). Both the early postoperative and 1-year angiographies demonstrated significantly lower overall graft patency rates in group 1 than in group 2 (early: 90.9% vs 99.1%, p<0.001; 1 year: 78.8% vs 95.1%, p<0.001), which might be affected by the lower vein graft patency rates in group 1 (early: 86.4%; 1 year: 67.9%). There was no difference in the 1-year patency of internal thoracic arteries between the two groups (94.3% vs 95.6%, p=0.402). Multivariate analysis demonstrated the use of vein graft (Odds ratio=5.204, p<0.001) as an independent predictor of graft failure during the first postoperative year. Target vessel revascularization rate during the postoperative 1 year was significantly higher in group 1 than in group 2 (7.4% vs 2.0%, p=0.002).

CONCLUSIONS

Our study revealed that saphenous vein graft use in OPCAB independently predicted the graft failure while increasing the target vessel revascularization rate during the first postoperative year. Exclusive arterial revascularization would be a preferable strategy in OPCAB.

De Vega annuloplasty for functional tricupsid regurgitation: concept of tricuspid valve orifice index to optimize tricuspid valve annular reduction

We evaluated long-term results of De Vega annuloplasty measured by cylindrical sizers for functional tricuspid regurgitation (FTR) and analyzed the impact of measured annular size on the late recurrence of tricuspid valve regurgitation. Between 2001 and 2011, 177 patients (57.9±10.5 yr) underwent De Vega annuloplasty for FTR. Three cylindrical sizers (actual diameters of 29.5, 31.5, and 33.5 mm) were used to reproducibly reduce the tricuspid annulus. Long-term outcomes were evaluated and risk factor analyses for the recurrence of FTR ≥3+ were performed. Measured annular diameter indexed by patient's body surface area was included in the analyses as a possible risk factor. Operative mortality occurred in 8 patients (4.5%). Ten-year overall and cardiac death-free survivals were 80.5% and 90.8%, respectively. Five and 10-yr freedom rates from recurrent FTR were 96.5% and 93.1%, respectively. Cox proportional hazard model revealed that higher indexed annular size was the only risk factor for the recurrence of FTR (P=0.006). A minimal P value approach demonstrated that indexed annular diameter of 22.5 mm/m(2) was a cut-off value predicting the recurrence of FTR. De Vega annuloplasty for FTR results in low rates of recurrent FTR in the long-term. Tricuspid annulus should be reduced appropriately considering patients' body size to prevent recurrent FTR.

Clinical Outcomes of Repeat Aortic Valve Replacement for Subaortic Pannus in Mechanical Aortic Valve

BACKGROUND

This study aimed to evaluate the early and late clinical outcomes after repeat aortic valve replacement (AVR) for subaortic pannus in patients with mechanical valves.

METHODS AND RESULTS

Between 2001 and 2017, 51 patients (median age, 59 years; 42 women) with prosthetic aortic stenosis (AS) caused by pannus ingrowth underwent repeat AVR because of acute malfunction of monoleaflet valve (3 patients), severe prosthetic AS (30 patients), and moderate prosthetic AS at the time of tricuspid or mitral valve surgery (18 patients). The median follow-up duration was 100 (interquartile range, 64-138) months. Double valve replacement was performed in 45 (88%) patients. Median time interval from previous operation was 161 (interquartile range, 121-194) months. The explanted mechanical AV was monoleaflet and bileaflet in 16 (31%) and 34 (67%) patients, respectively. Concomitant procedures included 16 mitral valve replacements (14 repeat) and 36 tricuspid valve surgeries (15 replacements, 21 repairs). No hospital deaths or cases of heart block occurred. Overall survival and event-free survival rates at 10 years were 88% and 51%, respectively. Late complications included recurrent prosthetic AS (4 patients), new paravalvular leakage of the mitral valve (5 patients), and severe tricuspid regurgitation (2 patients).

CONCLUSIONS

Although repeat AVR for subaortic pannus had acceptable early and late survival, recurrent prosthetic AS was frequently observed during late follow-up.

Initial experience with total thoracoscopic ablation

Background

Recently, a hybrid surgical-electrophysiological (EP) approach for confirming ablation lines in patients with atrial fibrillation (AF) was suggested. The aim of this approach was to overcome the limitations of current surgery- and catheter-based techniques to yield better outcomes.

Methods

Ten consecutive patients with AF underwent total thoracoscopic ablation (TTA) following transvenous catheter EP ablation (residual gap and cavotricuspid isthmus [CTI] ablation). Holter monitoring was performed 6 months postoperatively.

Results

Ten patients (90% with persistent AF) underwent successful hybrid procedures, and there was no in-hospital mortality. An EP study was performed in 8 patients and showed that successful antral ablation in all pulmonary veins was achieved in 7 of them. The median follow-up duration was 7.63 months (range, 6.7 to 11.6 months). Nine patients underwent Holter monitoring 6 months postoperatively, and the results indicated an underlying sinus rhythm without AF, atrial flutter, or atrial tachycardia lasting more than 30 seconds in all of the patients. There was no recurrence of AF during follow-up.

Conclusion

A hybrid approach that consists of TTA followed by transvenous catheter EP ablation (residual gap and CTI ablation) yielded excellent outcomes in our patient population. A hybrid approach should be considered in patients with a high risk of AF recurrence.

Aortic wrapping for a dilated ascending aorta in bicuspid aortic stenosis

BACKGROUND

Ascending aorta wrapping is rarely recommended for the management of dilated aorta, because of late complications. The aim of the present study was to analyze the early and late outcomes of the aortic wrapping technique at the time of aortic valve replacement (AVR) for bicuspid aortic stenosis (BAS).

METHODS AND RESULTS

Among patients who underwent primary AVR for BAS between 2002 and 2011, 79 who underwent ascending aortic wrapping (wrapping group) were compared with 144 patients who underwent AVR alone. The preoperative ascending aortic diameters were larger in the wrapping group (40.9±4.2 mm vs. 48.6±4.0 mm, P<0.001). Operative technique was to wrap the ascending aorta transversely with a semi-elliptically resected Dacron graft. The follow-up for the wrapping group was 76.5±35.5 (median 71.1) months. There were no early deaths. Early and late morbidity did not differ between groups. The 24 late deaths, including 10 cardiac-related deaths, occurred in the entire group; 3 sudden deaths occurred only in the AVR group. The 10-year overall survival in the wrapping group was higher than the AVR group (88.1±6.8% vs. 80.0±4.6%, P=0.048). No late aortic complications were detected. The aortic diameter was reduced from 49.5±4.1 mm to 45.3±5.0 mm after wrapping (P<0.001).

CONCLUSIONS

The aortic wrapping technique may be an option for treating a moderately dilated ascending aorta in selected patients undergoing AVR for BAS. Longer follow-up, however, is necessary to verify later complications.

Mid-Term Results of Totally Thoracoscopic Ablation in Patients with Recurrent Atrial Fibrillation after Catheter Ablation

Background

We investigated the impact of previous catheter ablation (CA) on the midterm outcomes of totally thoracoscopic ablation in patients with lone atrial fibrillation (AF).

Methods

Between February 2012 and July 2018, 332 patients underwent totally thoracoscopic ablation for the treatment of AF (persistent AF; n=264, 80%). The patients were stratified into CA (n=47, 14%) and non-CA (nCA; n=285, 86%) groups according to their CA history.

Results

All the baseline clinical characteristics and risk factors were similar between the groups except for age, percentage of male patients, prevalence of paroxysmal AF, prior percutaneous coronary intervention, and left atrial volume index (LAVI). No significant intergroup differences were observed in the incidence of early and late complications. At late follow-up, normal sinus rhythm was observed in 92% (43 of 47) of the patients in the CA group and 85% (242 of 285) of the patients in the nCA group (p=0.268). The rate of freedom from AF recurrence at 5 years was 55.3%±11.0% in the CA group, which was similar to that in the nCA group (55.7%±5.1%, p=0.690). In Cox regression analysis, preoperative brain natriuretic peptide levels and LAVI were associated with AF recurrence, but CA history was not significant.

Conclusion

Totally thoracoscopic ablation was safe and effective in treating AF irrespective of CA history. A history of CA did not appear to affect the procedural complexity.