Mitral annular calcification in patients undergoing aortic valve replacement for aortic valve stenosis.

Limited data exis t on clinical relevance of aortic valve stenosis (AVS) and mitral annular calcification (MAC), although with similar pathophysiologic basis. We sought to reveal the prevalence of MAC and its clinical features in the patients undergoing aortic valve replacement (AVR) for AVS. We reviewed 106 consecutive patients who underwent isolated AVR from 2004 to 2010. Before AVR, CT scans were performed to identify MAC, whose severity was graded on a scale of 0-4, with grade 0 denoting no MAC and grade 4 indicating severe MAC. Echocardiography was performed before AVR and at follow-up over 2 years after AVR. MAC was identified in 56 patients with grade 1 (30 %), 2 (39 %), 3 (18 %), and 4 (13 %), respectively. Patients with MAC presented older age (72 ± 8 versus 66 ± 11 years), higher rate of dialysis-dependent renal failure (43 versus 4 %), and less frequency of bicuspid aortic valve (9 versus 36 %), when compared to those without MAC. No significant differences were seen in short- and mid-term mortality after AVR between the groups. In patients with MAC, progression of neither mitral regurgitation nor stenosis was observed at follow-up of 53 ± 23 months for 102 survivors, although the transmitral flow velocities were higher than in those without MAC. In conclusion, MAC represented 53 % of the patients undergoing isolated AVR for AVS, usually appeared in dialysis-dependent elder patients with tricuspid AVS. MAC does not affect adversely upon the survival, without progression of mitral valve disease, at least within 2 years after AVR.

Impact of secondary hyperparathyroidism on ventricular mass regression after aortic valve replacement for aortic stenosis in hemodialysis-dependent patients.

In hemodialysis (HD)-dependent patients, secondary hyperparathyroidism induces cardiac hypertrophy. This study investigated whether parathyroid hormone (PTH) levels affect the degree of left ventricular (LV) mass regression in HD patients after aortic valve replacement (AVR) for aortic stenosis (AS). We retrospectively obtained preoperative and 2-year postoperative echocardiography and intact PTH measurements in 88 HD patients who underwent AVR, with bioprostheses (n = 35, 40%) and mechanical valves (n = 53, 60%) of effective orifice area >0.80 cm2/m2, between January 1997 and December 2010. The LV mass decreased significantly from 308 ± 88 to 217 ± 68 g at follow-up of 28 ± 4 months after AVR (p < 0.001). The LV mass regression at follow-up was inversely related to preoperative PTH values (R = 0.44, p = 0.001). The LV mass regression at follow-up was significantly smaller in the patients (n = 47) with PTH ≥100 pg/mL than in those (n = 41) with PTH <100 pg/mL throughout the study period (61 ± 75 versus 108 ± 49 g, p < 0.0001). After adjusting for female sex, hypertension, and baseline LV mass, high PTH values were found to be independent predictor of less LV mass regression at 2-year follow-up (ß = 0.23, r2 = 0.24, p = 0.02). In conclusion, the HD patients with high levels of PTH presented with less LV mass regression after AVR for AS without patient-prosthesis mismatch. Secondary hyperparathyroidism may impair regression of cardiac hypertrophy after AVR in HD patients with AS.

Early and late outcomes of coronary artery bypass surgery versus percutaneous coronary intervention with drug-eluting stents for dialysis patients.

BACKGROUND: Advances in percutaneous coronary intervention (PCI) using drug-eluting stents (DES) have impacted clinical practice. However, the efficacy of DES for dialysis patients still remains controversial. This study compares the early and long-term clinical outcomes of coronary artery bypass grafting (CABG) and PCI with DES in dialysis patients. METHODS: A retrospective review was performed in 125 dialysis patients treated between 2004 and 2007. Fifty-eight patients underwent CABG and 67 underwent PCI with DES. The overall death, cardiac death, and cardiac-related event rates were analyzed using the Kaplan-Meier method. For the risk-adjusted comparisons, multivariable logistic and Cox regression analyses were used. RESULTS: The preoperative characteristics of the patients were similar except for the ejection fraction (p = 0.002) and the number of diseased vessels (p < 0.001). The 30-day mortality was 0 in both groups. The overall survival rates at one, three, and five years were 84.2%, 64.7%, and 56.2% in CABG group and 88.2%, 75.5%, and 61.7% in DES group, respectively (p = 0.202). The rates of freedom from cardiac-related events at one, three, and five years were 76.6%, 68.1%, and 48.6%, and 63.0%, 31.4%, and 0% in CABG and DES groups (p < 0.001), respectively, including seven (10%) late thromboses in the DES group. Although the risk-adjusted analysis showed no significant difference for overall and cardiac death rates, the rates of cardiac-related events and graft/stent failure were significantly higher in the DES group. CONCLUSIONS: CABG is superior for revascularization in dialysis patients compared with PCI using DES in terms of freedom from cardiac-related events.

Bilateral versus single internal thoracic artery grafting in hemodialysis patients.

BACKGROUND: The use of the bilateral internal thoracic arteries (BITAs) during myocardial revascularization reportedly provides a survival benefit over using a single internal thoracic artery (SITA). However, the advantages in chronic hemodialysis patients, who generally have multiple comorbidities, is unclear. METHODS: Outcomes of chronic hemodialysis patients who underwent isolated coronary artery bypass grafting (CABG) using a SITA with additional saphenous vein grafts (SVGs) (n = 33) or BITAs (n = 30) for left-side revascularization were retrospectively reviewed. RESULTS: With the exception of the rate of diabetes mellitus (SITA vs. BITA: 84.8% vs. 50.0%; p = 0.003), the two groups showed similar patient characteristics. Using the off-pump technique, revascularization was completed without manipulation of the ascending aorta in 45.7% of patients in the BITA group, whereas all patients in the SITA group required aortic manipulation (p < 0.001). Of note, the incidence of extensive aortic calcification (>50% of ascending aorta circumference) was not uncommon (14.3%). The in-hospital mortality (3.0% vs. 0%, p = 0.336) and complication rates (including deep wound infection, re-exploration and stroke) were similar in both groups. The 5-year estimated survival rates for freedom from overall death in the SITA and BITA groups were 42.4% and. 57.4%, respectively (p = 0.202). CONCLUSIONS: BITA grafting was able to achieve revascularization with minimal manipulation of the diseased ascending aorta without increasing the complication rate. The long-term survival benefit of BITA grafting, however, was unclear in dialysis patients, especially because such patients have a relatively short life expectancy.

The long-term patency of a gastroepiploic artery bypass graft deployed in a semiskeletonized fashion: predictors of patency.

OBJECTIVES: Whether or not using the gastroepiploic artery (GEA) is associated with improved outcomes of coronary artery bypass grafting (CABG) remains unclear. Previous research has shown that the short-term function of the GEA was strongly associated with the degree of native vessel stenosis. We assessed the association between long-term GEA patency and the degree of stenosis of the coronary artery. METHODS: We retrospectively examined 517 patients who underwent CABG with an in situ semiskeletonized GEA from January 2000 to January 2015. In this cohort, 282 (54.5%) patients underwent distant radiological evaluations for >1 year post-surgery (range 1-18 years after surgery). Quantitative coronary angiography was used to measure the degree of stenosis of the native coronary artery. Preoperative angiographic parameters include the minimal lumen diameter (MLD) and the percentage of target vessel stenosis. A multivariable stepwise Cox proportional hazards regression analysis was used to identify predictors of angiographic occlusion. RESULTS: The cumulative patency rate of the GEA was 79.3% at 10 years. A multivariable analysis showed that an MLD (hazard ratio 4.43, 95% confidence interval 3.25-6.82; P < 0.001) was an independent risk factor of GEA occlusion. A time-dependent receiver operating characteristic (ROC) curve analysis identified that an MLD >1 mm was set as the cut-off value for graft occlusion. Patients with an MLD <1 mm had a 10-year patency rate of 89.8%. CONCLUSIONS: The long-term patency of the semiskeletonized GEA was acceptable. The target vessel MLD obtained using quantitative coronary angiography was a strong predictor of patency. Good long-term patency can be expected for an MLD <1 mm.

Ascending Aortic Aneurysm in a Child With Fibulin-4 Deficiency.

EFEMP2 (alias FBLN4) encodes extracellular matrix protein fibulin-4, and its mutation is associated with autosomal recessive cutis laxa type 1B and leads to severe aortopathy with aneurysm formation and vascular tortuosity. A 4-month-old child presented with a large ascending aortic aneurysm, and genetic testing revealed an EFEMP2 mutation. We achieved successful repair of the ascending aortic aneurysm at 33 months of age and report the macroscopic and microscopic findings.

Superior mesenteric artery plasty for type A acute aortic dissection with visceral ischemia.

Treatment of visceral ischemia complicated with acute type A aortic dissection is controversial. We had two cases of acute type A aortic dissection complicated by superior mesenteric artery (SMA) ischemia and successfully treated them with direct SMA perfusion during central aortic repair followed by SMA plasty. The presented procedures can be an option to treat visceral ischemia with a standard operative theater and equipment.

Learning curve of coronary surgery by a cardiac surgeon in Japan with the use of cumulative sum analysis.

OBJECTIVE: Case-volume has been believed to be of paramount importance in becoming a good cardiac surgeon. However, for a training cardiac surgeon there is no evidence regarding the specific number of necessary cases to attain the medico-legally acceptable level. We attempted to observe the learning curve in performing coronary surgery with the use of the cumulative sum (CUSUM) method to provide some evidence. METHODS: From April 2000 to March 2004, a cardiac surgeon, being board-certified but not being on the attending staff, performed 50 coronary artery bypass grafting (CABG) under supervision of three different chief attending surgeons at three different hospitals. His learning curve was analyzed with the use of CUSUM. Mortality and morbidity and the average time of crossclamp and operation at each hospital were examined. Also, the learning curve of 100 left internal mammary artery (LIMA) harvestings were analyzed via CUSUM in terms of harvesting time and injury rate. RESULTS: The CUSUM curve tended to come closer to the alert line (0.80 confidence) until the 23rd case, but never reached the alert line thereafter until the 50th case. The CUSUM curve never transgressed the alarm line (0.95 confidence) throughout 50 cases. The CUSUM curve of LIMA harvesting approached the alert line in the 38th case and the 59th case, but thereafter never reached the alert line and remained below the reassurance line from the 73rd case. CONCLUSION: Tentatively, it is inferred that approximately 23 cases of CABG may be sufficient to allow for independent practice and that 73 cases of LIMA harvesting are sufficient to allow independent practice.

Valve selection for the aortic position in dialysis patients.

BACKGROUND: Prosthetic valve selection in dialysis patients remains controversial because of the limited data available. This study aimed to clarify late clinical outcomes and discuss strategies for optimal valve selection in dialysis patients. METHODS: We retrospectively analyzed the data obtained from 406 consecutive patients who underwent aortic valve replacement between 1995 and 2010. We compared valve-related outcomes among 89 dialysis and 317 nondialysis patients. We selected bioprostheses for all patients older than 65 to 70 years, irrespective of the renal function. RESULTS: Dialysis was found to be a significant risk factor for bleeding events (hazard ratio, 3.98; 95% confidence interval, 2.51 to 6.30; p < 0.001), however, no significant differences were observed according to the type of prosthesis. The overall survival was significantly worse in the dialysis patients (63% versus 85% at 5 years; p < 0.001), and freedom from structural valve deterioration was also lower in the dialysis patients (82% versus 100% at 5 years; p < 0.001). Among the dialysis patients, an advanced age (≥ 70 years; hazard ratio, 3.53; p = 0.011), diabetes mellitus (hazard ratio, 2.48; p = 0.041), and concomitant coronary artery bypass grafting (hazard ratio, 1.99; p = 0.071) were independent predictors for late death based on a multivariate analysis. CONCLUSIONS: Our valve selection criteria in dialysis patients, which are the same as the current practice guidelines for nondialysis patients, are acceptable. Bioprostheses can be considered in all dialysis patients with diabetes or coronary artery disease.

Echocardiographic evaluation of internal mammary artery graft patency.

The feasibility of using transthoracic echocardiography to assess internal mammary artery graft patency and function was examined. Coronary angiography and transthoracic echocardiography was performed in 60 consecutive patients undergoing coronary artery bypass from April 2000 to March 2002. Flow velocity, velocity-time integral, and the ratio of the diastolic fraction of the velocity-time integral to total velocity-time integral were measured by doppler transthoracic echocardiography. A stress test was carried out to detect coronary flow changes by echocardiography. The relationship between the coronary angiogram and the echocardiogram was analyzed. The overall graft patency rate was 98%. The mean diastolic velocity-time integral in patients with patent grafts was 0.64, and it increased up to 0.72 in response to physical stress. The occluded grafts showed diastolic velocity-time integral fractions of less than 0.60 in all grafts. There was a statistical correlation between patency > or = FitzGibbon grade B and diastolic velocity-time integral > 0.60. The diastolic velocity-time integral recorded by transthoracic echocardiography predicted the patency of internal mammary artery grafts. As echocardiography is noninvasive and accurate, it might be a useful method of verifying arterial graft patency.

Successful repair of supravalvular aortic stenosis with ostial stenosis of the left coronary artery using Brom's three patch technique.

Stenotic lesion of the left coronary artery is an unnoticed but complicating feature of supravalvular aortic stenosis (SAS). We present successful repair of SAS with left coronary ostial stenosis. A 9-year-old girl was diagnosed as Williams syndrome associated with SAS. She had no symptoms of angina but cardiac catheterization revealed severe stenosis of the left coronary artery ostium. We adopted Brom's three patch technique, which could enlarge the aortic root and ostial lesion of left coronary artery inclusively. This method is also ideal regarding restoration of the aortic root geometry.

Less invasive surgical closure of patent ductus arteriosus in extremely low birth weight infants.

Minimally invasive surgery is widely used in pediatric surgery. Extremely low birth weight infants (ELBWI) are literally so fragile to surgical stress that the minimum invasive procedures should be required. We report 15 ELBWI cases with patent ductus arteriosus (PDA), who underwent surgical closure. All of them had failed treatment with indomethacin to close PDA or had contraindicated to its use. The mean gestational age at birth was 26.0+/-2.7 weeks (24-34 weeks) and birth weight 702+/-140 g (479-966 g). The mean age at operation was 23+/-11 days (2-48 days) and body weight at operation 679+/-151 g (428-969 g). The surgery-related mortality was none. No complications were also encountered. Our surgical procedures consist of 2 modalities, one is clipping PDA, not ligation. Clipping technique attributes to minimize the dissection of surrounding tissue of PDA. The other is posterolateral muscle sparing thoracotomy, which would reduce long-term physical impairment and deformity. We believe our surgical technique can be accomplished safely and would be an alternative approach for ELBWI with a lower probability of PDA closure with indomethacin or an increased risk of complications for medical treatment.

Bad aorta.

As its outcomes improve, cardiac surgery has been performed on more and more cases which were previously considered to be difficult to deal with. However, there are still a number of problems to be solved regarding surgery on patients with severe sclerotic lesions in the ascending aorta, which we collectively call "bad aorta". Concerning a preoperative assessment of the ascending aorta, our report revealed no relationship between the severity of calcification detected with a preoperative non-enhanced CT and the aortic lesion found during the surgery. Meanwhile, an intraoperative epiaortic ultrasound enables us to make high-quality evaluations of the aorta without imposing much burden on the patient. This modality may be essential for cardiac surgery. As for surgical management for bad aorta, quite a few methods have been reported to this point, but the overall operative mortality rate and cerebrovascular accident rate are relatively high, at a little <10 %, respectively. With the recent cross-clamping method under short-term total circulatory arrest (TCA), however, the results are much better; these rates total around 5 %. Further improvement is expected in the outcome of cardiac surgery on bad aorta cases by establishing a modality to evaluate sclerotic lesions in the ascending aorta with epiaortic ultrasound and by selecting a proper procedure for each case.

Clinical validation of coronary artery flow through an intracoronary shunt during off-pump coronary artery bypass grafting.

OBJECTIVES: Intracoronary shunts have been developed for a bloodless field and preserved forward flow preventing ischemia during off-pump coronary artery bypass (OPCAB) surgery. However, reports directly measuring the forward flow through the shunt in clinical settings are lacking. METHODS: Using a 7.5-MHz Doppler probe, we investigated the coronary flow through a 1.5-mm shunt inserted into the left anterior descending artery (LAD) for anastomosis with the internal thoracic artery during OPCAB in 30 consecutive patients. The following Doppler flow parameters were obtained before and after shunting: peak velocity, mean velocity, time-velocity integral, and flow. RESULTS: No patients developed significant electrocardiographic changes and the peak value of postoperative myocardial band of creatine kinase was 17 ± 16 IU/L. All Doppler flow parameters of the LAD decreased significantly after shunting; peal velocity: 71.3 ± 34.6 cm/second to 54.5 ± 25.3 cm/second (-24% ± 27%), mean velocity: 33.3 ± 18.3 cm/second to 26.3 ± 14.0 cm/second (-21% ± 23%), and time-velocity integral: 28.7 ± 12.1 cm to 19.0 ± 7.1 cm (-28% ± 14%), and flow: 38.7 ± 16.8 mL/minute to 25.0 ± 9.5 mL/minute (-31% ± 13%) (P < .01). CONCLUSIONS: The LAD flow is preserved at least 50% through a 1.5-mm intracoronary shunt, although the flow pattern was attenuated, during OPCAB anastomosis. The Doppler evaluation of the coronary artery flow before and after shunting is useful to justify the protective use of the shunt on myocardial perfusion during OPCAB.

Effects of the side of arteriovenous fistula on outcomes after coronary artery bypass surgery in hemodialysis-dependent patients.

OBJECTIVE: The aim of the study was to determine whether using the in situ internal thoracic artery (ITA) graft ipsilateral to the arteriovenous fistula adversely affects the outcomes after isolated coronary artery bypass grafting (CABG) in the dialysis-dependent patients to answer the concerns of a possible steal and consequent myocardial ischemia. METHODS: We categorized 155 dialysis patients undergoing isolated CABG between January 1993 and December 2011 into 108 patients (70%, ipsilateral group) whose left anterior descending artery (LAD) was revascularized with the ITA ipsilateral to the arteriovenous fistula and 47 patients (contralateral group) whose LAD was grafted with the ITA opposite to the fistula, to compare their early and late outcomes. RESULTS: While 94% of the ipsilateral group had left fistula, 55% of the contralateral group had left fistulas. The LAD was grafted with the left ITA in 94% of the ipsilateral group, whereas it was grafted with left (49%) or right (51%) ITAs in the contralateral group. There was no significant difference in hospital mortality between the groups (ipsilateral 10.2% vs contralateral 10.6%). After follow-up for 55 ± 42 months, the overall survival (ipsilateral 58% vs contralateral 65% at 5 years) and cardiac event-free rates (ipsilateral 74% vs contralateral 68% at 5 years) were also similar between the groups by log-rank tests (P = .90 and P = .07). CONCLUSIONS: Revascularization of the LAD using the in situ ITA graft ipsilateral to the arteriovenous fistula increases neither the operative mortality nor the risks of late death and cardiac events after isolated CABG in dialysis patients.

Recent risk factors for open surgical mortality in patients with ruptured abdominal aortic aneurysm.

AIM: We examined recent relevant prognostic factors for the outcome of open surgical treatment of ruptured abdominal aortic aneurysm. METHODS: Between 2006 and 2012, 35 patients received emergency open surgical treatment for ruptured abdominal aortic aneurysm at our institute. We reviewed ambulance activity logs and clinical records of 34 infrarenal ruptured abdominal aortic aneurysm patients retrospectively. Univariate and multivariate logistic regression analyses were carried out to identify risk factors for surgical outcomes. RESULTS: Eight patients died during surgery or within a few hours following surgery completion. Through univariate analysis, body mass index, serum lactate level, arterial blood pH, base excess, platelet count, prothrombin time-international normalized ratio, activated partial thromboplastin time, type of ruptured aneurysm, response to i.v. fluid resuscitation within 2,000 mL in the initial therapy, and volume of blood loss during surgery were detected to be significant variants. Multivariate logistic regression analysis revealed the patients who were hemodynamically stabilized after primary volume loading had a 13.2 times higher possibility of survival. Body mass index, high serum lactate level, and volume of blood loss were also found to be independent risk factors of mortality. CONCLUSION: The risk factors of open surgical ruptured abdominal aortic aneurysm repair, body mass index, lactate level, volume of intraoperative blood loss, and response to initial 2,000 mL fluid resuscitation were correlated to survival.

Predictors for early and late outcomes after coronary artery bypass grafting in hemodialysis patients.

BACKGROUND: Markedly higher hospital and long-term mortality after coronary artery bypass grafting (CABG) have been reported in hemodialysis (HD)-dependent patients. We tried to identify the predictors for short-term and long-term outcomes after CABG, which have not been well studied. METHODS: Between 1993 and 2010, 152 patients undergoing HD (117 men; HD duration of 8.7±8.0 years) underwent isolated CABG. Our strategies included use of a single internal thoracic artery (ITA) in patients with diabetes mellitus (DM), bilateral ITAs in patients without DM, and possible avoidance of cardiopulmonary bypass (CPB) after 2003. RESULTS: Thirty-six percent of patients underwent conventional CABG: 20% had on-pump beating heart procedures and 44% had off-pump procedures, with 2.8±1.0 anastomoses. Hospital mortality was 10.6% with improvement to 6.8% after 2003. Predictors for hospital death were left ventricular ejection fraction (LVEF) less than 0.40 (p=0.042), use of CPB (p=0.046), and postoperative need for continuous hemofiltration (p=0.037). After follow-up of 49±42 months, the overall survival rates were 76.9%, 60.0%, 43.9%, and 36.2% and the cardiac events-free rates were 77.0%, 70.1%, 55.9%, and 44.8% at 3, 5, 8, and 10 years, respectively, in the Kaplan-Meier model. A multivariate Cox proportional hazard model identified age older than 63 years (p=0.014), DM (p=0.036), and peripheral artery disease (PAD) (p=0.044) as predictors for late death, and DM (p=0.038) and LVEF less than 0.40 (p=0.027) as predictors for late cardiac events. CONCLUSIONS: Although early outcomes have been improved by off-pump techniques, late outcomes are not satisfactory in patients who rely on HD and undergo CABG. To improve late outcomes we may need aggressive management of DM, PAD, and low LVEF in those patients.

Can we predict the site of entry tear by computed tomography in patients with acute type a aortic dissection?

BACKGROUND: In patients with acute type A aortic dissection (AAD), localization of the primary entry tear to be excluded is of major importance for intervention. HYPOTHESIS: There are reliable indirect computed tomography (CT) findings to predict the entry site. METHODS: In 83 patients with type A AAD whose primary entry tears were identified surgically between 2003 and 2009, we retrospectively examined the diagnostic CT scans regarding pericardial effusion, the largest short-axial diameter of the aorta, widths of true and false lumens, and false lumen thrombosis at 6 levels of thoracic aorta from the aortic root to the descending aorta. RESULTS: The primary entry sites identified intraoperatively were proximal ascending in 21 patients, middle ascending in 21, distal ascending in 21, arch in 17, and descending or unknown in 16. The multivariate logistic analysis revealed that pericardial effusion (odds ratio [OR]: 2.2, 95% confidence interval [CI]: 1.2-3.4, P < 0.001) and dilated ascending aorta (OR: 1.6, 95% CI: 1.1-2.4, P = 0.012) were the significant CT findings to predict the entry tear in the ascending aorta. It also revealed that the significant CT finding to predict the entry tear distal to the aortic arch was nonthrombosed false lumen in the descending aorta (OR: 1.2, 95% CI: 1.1-2.1, P = 0.048). CONCLUSIONS: We can predict the primary entry site by the preoperative CT findings in patients with type A AAD, considering pericardial effusion, aortic diameter, widths of true and false lumens, and false lumen thrombosis at different anatomic levels.