Yusuke Shimahara

Late Aortic Insufficiency Related to Poor Prognosis During Left Ventricular Assist Device Support

BACKGROUND Management of native aortic insufficiency (AI) during left ventricular assist device (LVAD) support is challenging. We investigated the occurrence of de novo AI during long-term LVAD support to identify its effect on late clinical and echocardiographic outcomes. METHODS Left ventricular assist devices were implanted in 99 patients with dilated cardiomyopathy, of whom 47 without preoperative AI were investigated using serial echocardiography examinations for more than 1 year after the operation. RESULTS The mean duration of LVAD support was 838±327 days, and 26 patients (55%) were supported for more than 2 years. Twenty-nine patients (62%) had no AI (group A), whereas de novo AI developed in the remaining 18 (38%; group B) at 1 year after LVAD implantation (≥grade 2 in 5, grade 1 in 13). The LV end-diastolic diameter was significantly reduced after LVAD implantation in both groups, with no significant difference between them. Overall survival was better in group A (p=0.0195). Multivariate analysis revealed that preoperative mitral regurgitation of more than grade 2 (odds ratio, 7.8; 95% confidence interval, 1.2 to 48.6; p=0.028) and an aortic valve that remained closed at 1 month after implantation (odds ratio, 6.7; 95% confidence interval, 1.0 to 43.9; p=0.048) were significant independent predictors of de novo AI at 1 year after LVAD implantation. CONCLUSIONS Survival was significantly worse when de novo AI developed in patients during long-term LVAD. Our findings indicate that preoperative functional mitral regurgitation and postoperative aortic valve opening are related to the progression of AI during long-term LVAD support.

Risk Analysis of Bloodstream Infection During Long-Term Left Ventricular Assist Device Support

BACKGROUND Infection during left ventricular assist device (LVAD) support is associated with a high mortality. This study investigated the effect of bloodstream infection on survival of patients with LVAD support and assessed risk factors for survival in LVAD patients with bloodstream infection. METHODS Between 1999 and 2010, 109 consecutive patients with end-stage heart failure were supported by an LVAD as a bridge to transplantation. Overall survival was compared between those with and without a bloodstream infection. Risk factors for survival of patients with bloodstream infection were analyzed. RESULTS A bloodstream infection developed in 65 patients (60%) during 584 ± 389 days of LVAD support. Compared with patients without a bloodstream infection, overall survival was significantly worse in those with bloodstream infection (68% vs 84% at 2 years after LVAD implantation, p = 0.0117). However, of 22 patients bridged to transplantation, none had bloodstream infection recurrence after transplantation, and their 3-year survival rate after transplantation was 100%. Cox multivariate analysis (hazard ratio [95% confidence interval]) identified postoperative right ventricular failure (2.890 [1.238 to 6.757]; p = 0.0141) and bloodstream infection caused by a pathogen other than gram-positive cocci (3.336 [1.390 to 8.006] p = 0.0070) as significant risk factors for death in LVAD patients with a bloodstream infection. CONCLUSIONS Bloodstream infection had a significant effect on survival after LVAD implantation. Our results suggest that urgent cardiac transplantation should be considered for LVAD patients with a bloodstream infection based on the causative organism and right ventricular function.

Long-term outcome of combined valve repair and maze procedure for nonrheumatic mitral regurgitation.

OBJECTIVE The long-term outcomes of combined mitral repair and maze procedure for patients with nonrheumatic mitral regurgitation and chronic atrial fibrillation were evaluated. METHODS Between June 1992 and December 2008, 187 patients underwent a combined mitral repair and maze procedure. The mean follow-up period was 7.4 ± 4.3 years. Chordal reconstruction was performed in 69 patients, leaflet resection in 91, edge-to-edge leaflet suture in 30, and ring annuloplasty in 156. In addition, a cryo-maze procedure was applied in 110, and a Cox-Kosakai maze and radiofrequency maze were applied in the others. RESULTS There were 2 operative deaths and the 15-year survival was 71%. The 15-year freedom from greater than grade 3 mitral regurgitation was 61%; rates of freedom from heart failure (New York Heart Association class ≥ III) and reoperations were 79% and 91%, respectively. Cardiac function was improved and left ventricular size was decreased significantly postoperatively. Multivariate analysis showed that a large left ventricular diastolic diameter (≥65 mm) was an independent risk factor for recurrent mitral regurgitation. Eleven thromboembolic episodes (0.79%/patient-year) were detected during follow-up examinations, of which 7 occurred in patients with recurrent atrial fibrillation. Sinus rhythm was regained in 86% after 6 months and in 63% after 15 years. Multivariate analysis showed that a small-voltage f wave was an independent risk factor for AF recurrence. CONCLUSIONS A combined mitral valve repair and maze procedure provided low rates of morbidity and mortality and led to well-preserved cardiac function. Left ventricular diastolic diameter and f-wave voltage can be accurate predictors of good long-term outcome.

Angiographic evaluation of flow distribution in sequential and composite arterial grafts for three vessel disease

OBJECTIVES We sought to delineate the effects of the severity of target lesions and their combinations on the occurrence of competitive flow, especially in the composite Y-graft and to establish an optimal strategy for graft arrangement and patient selection. METHODS We reviewed early and late angiograms of 2514 bypass grafts in 601 patients, who underwent off-pump coronary revascularization to three-vessel vascular regions using the internal thoracic artery (ITA) and radial artery (RA) without aortic manipulation. As a standard technique, the left anterior descending artery (LAD) was bypassed with the in situ ITA, and the left circumflex and right coronary arteries (RCA) were bypassed with the composite RA. Bypass flow was graded as antegrade, competitive or no flow. RESULTS The early patency rate was 98.1% (2466/2514), while competitive flow was detected in 6.4% (162/2514). For the LAD, the individual and sequential in situ ITA provided lower incidence of competitive flow than the composite graft (0.3% (1/298) versus 7.6% (23/303), P < 0.0001). Regarding the RA to non-LAD bypass, 86.3% (113/131) of competitive flow occurred at the distal end of the I- or Y-graft, and the cumulative patency rate was significantly lower than that of sequential proximal anastomosis (80.1 versus 56.6% at 5 years, P < 0.0001). The number of sequential anastomoses did not affect the cumulative patency rate (P = 0.09). For the composite Y-graft to three-vessel regions, the rate of antegrade flow in patients with 76-100% stenosis in both the LAD and the RCA was 95.7% (178/186), which was significantly higher than that of 78.1% (100/128) in patients with 76-100% stenosis in the LAD and 51-75% stenosis in RCA (P < 0.0001). CONCLUSIONS Sequential and composite grafting was considered reliable, exclusively in appropriately selected situations. To secure entire patency of the Y-graft to three-vessel regions, balanced bypass flow toward LAD and RCA would be crucial.

Initial experience using Excimer laser for the extraction of chronically implanted pacemaker and implantable cardioverter defibrillator leads in Japanese patients

BACKGROUND Given the exponential growth in cardiac device implantations, the need for less invasive lead extraction is increasing. The Excimer laser was approved for lead removal in Japan in 2010. The present study reports the initial experience using this novel technique to extract chronically implanted pacemaker and implantable cardioverter defibrillator (ICD) leads from Japanese patients. METHODS AND RESULTS We performed a retrospective study of consecutive patients undergoing lead extraction using the laser sheath at a single Japanese center. Patient and lead characteristics, indications, and outcomes were analyzed. From August 2010 to September 2012, a total of 70 leads, including 14 ICD leads, were removed using the laser sheath from 40 patients (26 male, 14 female; age 65.5±18.3 [mean±SD] years; body mass index 21.8±3.5 kg/m2). The median implant duration was 87 months (range 13-328 months). Indications were infection (n=35), venous occlusion (n=4), and pain (n=1). The femoral approach was used in combination with the laser technique in five cases. Complete procedural success was achieved with 68 leads (97.1%). Although the electrode tip was left behind in the remaining two leads, the desired clinical outcomes could be achieved; which were defined as clinical success. No cases resulted in failure. There were no major complications, including death and bleeding requiring open-chest surgery. CONCLUSIONS Laser sheaths appear to provide a feasible and effective means of extracting chronically implanted pacemaker and ICD leads in Japanese patients.

Determinants for successful sequential radial artery grafting to the left circumflex and right coronary arteries

The aim of this retrospective observational study was to delineate determinants for antegrade flow and entire patency of the sequential radial artery graft (RAG) in the left circumflex artery (LCX) and right coronary artery (RCA). Angiograms of 432 RAGs, which were sequentially anastomosed to the LCX and RCA, and were proximally anastomosed with the in-situ internal thoracic artery as the composite I- or Y-graft, were studied. The mean targets of RAG were 2.83±0.79. We examined effects of characteristics of RAG and the targets, such as native coronary stenosis and their combinations, on competitive flow and occlusion. Of 432 RAGs, 413 (95.6%) were patent to all targets, while 331 (76.6%) provided antegrade flow to all targets in sequential anastomoses. By the univariate and multivariate analyses, 51-75% stenosis of the most distal target was identified as the significant predictor of competitive flow or occlusion (OR=8.59, P<0.0001). The cumulative graft patency rate of RAGs with 76-100% stenosis of the most distal target at 40 months was 88.6%, whereas that of RAGs with 51-75% stenosis of the most distal target was 59.1% (P<0.0001). In sequential RAG, severity of stenosis in the most distal target had the significant impact on prevention of competitive flow and long-term patency to all targets.

Hemodynamic Performance and Durability of Mosaic Bioprostheses for Aortic Valve Replacement, up to 13 Years

BACKGROUND This study evaluated the mid to long-term durability and hemodynamics of the small-size Mosaic bioprosthesis, a third-generation stented porcine bioprosthesis, for aortic valve replacement (AVR). METHODS AND RESULTS From 2000 to 2012, 207 patients (117 women; age, 74±8 years; body surface area, 1.48±0.25 m(2)) underwent AVR with a Mosaic bioprosthesis. The mean follow-up period was 3.5±2.7 years (maximum, 12.4 years) and the follow-up rate was 93.7%. A 19-, 21-, 23-, 25-, and 27-mm prosthesis was used in 103, 53, 35, 13, and 3 patients, respectively. The measured effective orifice area was 1.17±0.25, 1.29±0.19, 1.39±0.24, and 1.69 cm(2)for the 19-25 mm prostheses, and the mean transvalvular pressure gradient was 19.4±6.0, 18.5±5.8, 16.5±7.3, and 13.2±2.9 mmHg, respectively. The left ventricular mass regression was significant (P<0.05) with rates of 74.6±18.8%, 75.5±30.2%, 68.1±30.5%, 55.9±12.9%, and 49.2%, respectively. The 30-day mortality rate was 1.9% and the 5- and 10-year actuarial survival rates were 86.0% and 73.7%, respectively. Valve-related comorbidities occurred in 3 patients (structural valve deterioration [SVD] in 1 after 7.2 years, and prosthetic valve endocarditis in 2). Freedom from SVD at 10-year was 96.7%. CONCLUSIONS The mid to long-term performance of the small Mosaic bioprosthesis was satisfactory, with excellent hemodynamics and few valve-related adverse events.

Long-term echocardiographic follow-up of untreated 2+ functional tricuspid regurgitation in patients undergoing mitral valve surgery

OBJECTIVES Concomitant tricuspid valve surgery with mitral valve surgery is recommended for patients with severe functional tricuspid regurgitation (TR). However, the treatment for 2+ TR (mild TR) remains controversial. Here, we evaluated the long-term results of untreated 2+ TR in patients undergoing mitral valve surgery. METHODS We retrospectively reviewed the records of 96 patients with untreated 2+ TR among 885 patients who underwent mitral valve surgery from 2003 to 2010. Exclusion criteria were tricuspid valve surgery (TVS), emergency surgery, primary TR and pacemaker lead through the tricuspid valve. We assessed survival and freedom from heart failure. The freedom from 3+ (moderate) or 4+ (severe) TR was investigated by echocardiographic data at pre- and postoperative week 1, then at 1, 3, 5, 7 and 10 postoperative years, which were compared with those in patients who had 2+ TR preoperatively and underwent concomitant TVS in the same period (n = 47). RESULTS The mean follow-up was 7.1 ± 2.7 years. There was no 30-day mortality. The survival rate was 97.5% at 5 years and 87.5% at 10 years. The independent risk factors for mortality were age (OR 1.2, P = 0.03) and left ventricular ejection fraction (OR 0.9, P = 0.03). Untreated 2+ TR improved transiently within the first postoperative year (P < 0.001), but progressed again in the mid- to long term. Freedom from ≥3+ TR was 64.2% at 5 years and 46.7% at 10 years, which was significantly lower than that from ≥3+ TR in patients who underwent concomitant TVS (P = 0.006). The independent risk factors for TR progression (≥3 + TR) were age (OR 1.1, P = 0.005), atrial fibrillation (OR 2.2, P = 0.04) and tricuspid annular diameter (TAD) index (mm/m(2); OR 1.1, P = 0.02). Receiver operating characteristic curves showed that the optimal TAD index cut-off value was 21.0 for long-term survival [area under the curve (AUC) = 0.72] and 21.2 for TR progression (AUC = 0.64). CONCLUSIONS Although untreated, 2+ TR significantly improved after mitral valve surgery, it then progressed again in the mid- to long term. Therefore, concomitant TVS should be considered in patients with 2+ TR who have dilated tricuspid annulus or atrial fibrillation, if feasible.

Early Results of Simultaneous Transaortic Transcatheter Aortic Valve Implantation and Total Arterial Off-Pump Coronary Artery Revascularization in High-Risk Patients

BACKGROUND Transcatheter aortic valve implantation (TAVI) has become an alternative procedure for treating aortic stenosis (AS) in patients with advanced age and severe comorbidities. Ischemic heart disease (IHD) is present with AS in 40-50% of patients with typical angina. Considering the high operative mortality and morbidity rates in these patients, hybrid TAVI and off-pump CABG (OPCAB) have become realistic treatment options. METHODSANDRESULTS Between August 2014 and November 2015, 12 patients were evaluated for simultaneous TAVI and OPCAB. Because of their advanced age and comorbidities these patients were not considered suitable for standard open heart surgery. PCI was also considered unsuitable, because of left anterior descending artery (LAD) proximal lesions and/or high SYNTAX score. TAVI was conducted through a median sternotomy after left internal thoracic artery (LITA) to LAD anastomosis. In 11 cases OPCAB with LITA and composite RA graft was performed using an aorta no-touch technique. Mean age at operation was 81±6.3 years. Average number of distal anastomoses was 2.6. Perivalvular leakage was mild in 3 patients, trivial in 8, and none in 1. There was no conversion to on-pump procedure and no hospital deaths. CONCLUSIONS Simultaneous transaortic TAVI and OPCAB in high-risk patients with severe AS and IHD is a reasonable option. This method could be an alternative to surgical aortic valve replacement and CABG. (Circ J 2016; 80: 1946-1950).

Safety and efficacy of sequential and composite arterial grafting to more than five coronary branches in off-pump coronary revascularisation: assessment of intra-operative and angiographic bypass flow

OBJECTIVE We sought to delineate the safety and efficacy of sequential and composite coronary artery bypass grafting (CABG) with exclusively arterial grafts to more than five coronary branches including small coronary vessels. METHODS We reviewed the clinical records of 633 consecutive patients with 2617 bypass grafts who underwent total arterial off-pump complete revascularisation for three-vessel coronary regions without aortic manipulation. Group I consisted of 263 patients with a single in situ internal thoracic artery (ITA), while group II consisted of 370 patients with bilateral in situ ITA. Subgroups I-A and I-B consisted of 242 patients with three or four distal anastomoses and 21 patients with more than five distal anastomoses, respectively. Subgroups II-A and II-B consisted of 199 patients with three or four anastomoses and 171 patients with more than five anastomoses, respectively. RESULTS The early mortality and morbidity rate and the angiographic graft patency in the groups I and II were similar, while the rate of antegrade flow in group II (92.4%, 1349/1460) was significantly higher than that in group I (89.4%, 638/714, p=0.02). Intra-operative graft flow measured at the proximal portion of the in situ ITA in group II (79+/-35 ml min(-1)) was significantly larger that that in group I (53+/-31 ml min(-1), p<0.0001). The patency rate of bypass grafts to small coronary vessels (1.25 mm or less in diameter) was 97.4% (626/643). The early mortality rates in subgroups I-A and I-B were 1.2% (3/242) and 0% (0/21), respectively (p=0.61). The graft flow and incidence of competitive flow was comparable in subgroups I-A and I-B. The early mortality rates in subgroups II-A and II-B were 0.5% (1/199) and 0.6% (1/177), respectively (p=0.91). The graft flow to five or more coronary branches (81+/-35 ml min(-1)) was significantly greater than that to three branches (67+/-30 ml min(-1), p=0.01). CONCLUSIONS For more than five target branches, sequential and composite arterial grafting with the ITA and a radial artery was safe and reliable, even when the target vessels were small. Bilateral in situ ITA would be feasible for the patients with multiple stenotic lesions, because of abundant bypass flow and less incidence of competitive flow. Durable completeness of revascularisation can be expected.