Minimally Invasive versus Conventional Aortic Root Surgery: Results of an Intermediate-Volume Center

BACKGROUND

 We evaluate the outcome of aortic root surgery via an upper J: -shaped mini-sternotomy (MS) versus full sternotomy (FS) in an intermediate-volume center.

METHODS

 Between November 2011 and February 2019, 94 consecutive patients underwent aortic root surgery: 62 (66%) patients were operated via a J: -shaped MS (group A) and 32 (34%) patients via FS (group B). The primary endpoints were mortality, major adverse cardiac and cerebral events (MACCE), and reoperation in a 2-year follow-up. The secondary endpoints were perioperative complications and patient's satisfaction with the procedural results.

RESULTS

 Valve sparing root replacement (David procedure) was performed in 13 (21%) of the MS and 7 (22%) of the FS patients. The Bentall procedure in MS versus FS was 49 (79%) versus 25 (78%), respectively. Both groups presented similar mean operation, cardiopulmonary bypass, and cross-clamp times. Postoperative bleeding was 534 ± 300 and 755 ± 402 mL (p = 0.01) in MS and FS, respectively, erythrocyte concentrate substitution was 3 ± 3 and 5.3 ± 4.8 (p = 0.018) in MS and FS, respectively, and pneumonia rates were 0 and 9.4% (p = 0.03) in MS and FS, respectively. The 30-day mortality was 0% in both groups, whereas MACCE was 1.6 and 3% (p = 0.45) in MS and FS, respectively. After 2 years, the mortality and MACCE were 4.6 and 9.5% (p = 0.11) and 4.6 and 0% (p = 0.66) in MS and FS, respectively. The number of patients who were satisfied with the surgical cosmetic results in groups A and B was 53 (85.4%) and 26 (81%), respectively.

CONCLUSION

 Aortic root surgery via MS is a safe alternative to FS even in an intermediate-volume center. It offers a shorter recovery time and similar midterm results.

Outcomes in Patients with Left Bundle Branch Block after Rapid Deployment Aortic Valve Replacement

OBJECTIVES

Increased rates of postoperative left bundle branch block (LBBB) and permanent pacemaker implantation (PPI) frequently occur after implantation of rapid deployment valves. The impact of LBBB on follow-up outcomes remains controversial. So far, no data regarding long-term outcomes exist.

AIM

The aim of this study was to analyze the impact of LBBB on postoperative outcomes after rapid deployment aortic valve replacement (RDAVR).

METHODS

A total of 620 consecutive patients without preexisting LBBB or PPI who underwent rapid deployment AVR between March 2012 and September 2019 were included. New-onset LBBB was defined as any new LBBB that persisted at hospital discharge. The median follow-up time for clinical data was 1.7 years post-RDAVR.

RESULTS

At discharge, new-onset LBBB was seen in 109 patients (17.5%). There were no differences between the LBBB groups and no-LBBB groups regarding baseline characteristics. At a median follow-up of 1.7 years, no difference was found between LBBB groups and no-LBBB groups concerning all-cause mortality (12.8 vs. 11.7%; hazard ratio [HR]: 1.08; 95% confidence interval [CI]: 0.74-1.53; p = 0.54). Nevertheless, new-onset LBBB was associated with significant higher pacemaker implantation rates at follow-up (10.1 vs. 6.3%; HR: 3.58; 95% CI: 1.89-6.81 p < 0.001).

CONCLUSION

After a median follow-up of 1.7 years, new-onset LBBB was not associated with increased mortality. Nevertheless, higher pacemaker implantation rates were observed in patients with new-onset LBBB after RDAVR.

Early Results after Aortic Valve Replacement Using Last Generation Bioprosthetic Aortic Valve

INTRODUCTION

Few data are available about the newest generation surgical bioprosthesis. We aimed to evaluate early clinical and hemodynamic outcomes after using the INSPIRIS RESILIA aortic valve (Edwards Lifesciences, Irvine, California, USA).

METHODS

Between July 2018 and April 2021, 80 patients underwent aortic valve replacement receiving the INSPIRIS RESILIA aortic valve at our institution. Primary outcomes were the composite of early mortality, stroke, and myocardial infarction. Secondary outcomes were hemodynamic performances of the valve, paravalvular leakage, and new pacemaker implantation.

RESULTS

The mean age of the study population was 60.6 ± 8.3 years. The mean Society of Thoracic Surgery-Predicted Risk of Mortality score was 2.9 ± 1.7%. In 43.7% of the patients, concomitant surgery was performed. The in-hospital mortality, all-stroke, and myocardial infarction rates were 2.5%, 1.2%, and 1.2%, respectively. No valve was explanted and no redo was performed. The mean postoperative trans-prosthetic gradient at discharge was 10.2 ± 4.1 mm Hg. There was no need for new pacemaker implantation. We registered only two cases with minimal (trace) paravalvular leakage.

CONCLUSION

The use of the INSPIRIS RESILIA aortic valve in a young, low-risk population is safe and associated with very good early clinical and hemodynamic outcomes.

Transapical transcatheter aortic valve implantation in patients with aortic diseases

OBJECTIVES

Patients scheduled for transcatheter aortic valve implantation (TAVI) treatment frequently present with concomitant aortic diseases, in which case they are usually considered to be at high interventional risk and, in particular, unable to undergo the transfemoral TAVI approach. Since the establishment of the 'transfemoral first' strategy for TAVI, there has been an evidence gap with regard to the outcomes of such patients. We aimed to evaluate the mid-term outcomes after transapical TAVI in patients with diverse aortic diseases.

METHODS

Fifty-five consecutive elderly patients (78.4 years; standard deviation: 8.6 years) at intermediate surgical risk with severe aortic stenosis and aortic diseases (porcelain aorta 36%, ascending aneurysm 15%, descending aneurysm 26%, type-B dissection 4%, aortic thrombus 7%, Leriche syndrome 4%, aortic kinking 11%, aortic ulcer 2%, previous aortic operation 20%, aortic elongation/tortuosity 4%) underwent transapical TAVI treatment between January 2011 and November 2019 at our institution. We used the second-and third-generation self- and balloon-expanding valves. The follow-up time was 92.6 patient-years.

RESULTS

The Society of Thoracic Surgery-Predicted Risk of Mortality score was 7% (standard deviation: 4%). The 30-day mortality and all-stroke rates were 6% and 4%, respectively. The median survival time was 24.9 months (95% confidence interval 17.6-32.3). The median time of freedom from a composite of death and cardio-cerebral adverse events was 24.3 months (95% confidence interval 11.9-36.8). The rate of moderate/severe paravalvular leakage was 2%. The pacemaker rate was 10%. No early or late aortic syndrome occurred.

CONCLUSIONS

Transapical TAVI is a safe method and shows very promising early and mid-term outcomes, without early/late aortic syndrome, in patients with aortic diseases for whom transfemoral TAVI as the first-line transcatheter method might be contraindicated or not feasible.

Single-Center Outcomes with Rapid Deployment Aortic Valve Replacement

OBJECTIVES

 Rapid-deployment valves can reduce procedural times and may facilitate minimally invasive surgery. In our institution, more than 500 patients underwent rapid deployment aortic valve replacement (AVR).

METHODS

 A total of 510 patients underwent rapid deployment AVR between March 2012 and September 2017, of whom 270 patients underwent isolated AVR and 240 underwent AVR with concomitant procedures. The cumulative follow-up time was 1,444 patient-years, the median follow-up time 2.8 years, respectively RESULTS:  An early all-cause mortality of 3.5% (n = 18) was seen with a cumulative survival of 91.9 ± 2.2% after 12 months. Mean cross-clamp times were 37 ± 19 minutes for isolated AVR and 93 ± 29 minutes for AVR with concomitant procedures. The rate of new pacemaker implantation was 7.8% (n = 40). No case of structural degeneration occurred in the follow-up. Three (0.6%) cases of endocarditis were registered.

CONCLUSIONS

 Rapid deployment AVR can be performed safely with low complication rates and good hemodynamic results. Therefore, the relevance in aortic valve surgery can be stressed.

Minimally invasive aortic root surgery: Midterm results in a 2-year follow-up

OBJECTIVES

Minimally invasive surgery (MIS) via partial upper sternotomy (PUS) for aortic root surgery represents an alternative to the full median sternotomy (FMS). PUS offers less operative trauma. We analyzed the midterm outcome of root replacement (Bentall) or valve-sparing root replacement (David) via PUS to evaluate the safety of this access.

METHODS

Between November 2011 to April 2017, a total of 47 consecutive patients underwent aortic root surgery with aortic aneurysm and/or localized aortic dissection through Bentall or David operation through PUS mean age (57.9 ± 10.5 years). Bentall operation was performed in 36 patients (77%), whereas 11 patients (23%) received a David procedure. The outcome was carried out in 6-months, 1-year, and 2-years-follow up.

RESULTS

Mean operation time was 287.3 ± 72.6 minutes, mean cardiopulmonary bypass (CPB) time 174 ± 54.8 minutes, mean cross-clamp time 133 ± 33.1 minutes. Rethoracotomy-rate was (4.2%). Superficial wound healing disturbance was (2%) and no deep sternal infection or sternum instability occurred. Hospitalization-and intensive care unit-stay was 11.8 ± 4.4 and 1.9 ± 1.3 days with a total median ventilation-time of 10 (IQR 7.5-13.5) hours. There was no 30-day-mortality. After 2 years the total rate of mortality, major adverse cardiac and cerebrovascular events, and redo surgery was (6.3%, 4.2%, and 4.2%).

CONCLUSIONS

Minimally invasive aortic root surgery via partial upper sternotomy could be a safe alternative to the full median sternotomy. It requires longer operative times but reduces postoperative morbidity with good postoperative outcome.

Mid-Term Outcomes after Transapical and Transfemoral Transcatheter Aortic Valve Implantation for Aortic Stenosis and Porcelain Aorta with a Systematic Review of Transfemoral versus Transapical Approach

Background We have aimed to analyze early and mid-term outcomes of patients undergoing transapical/transfemoral transcatheter aortic valve implantation (TA-/TF-TAVI) for aortic stenosis and porcelain aorta (PAo) in our institution. Additionally, we postulated that the TA approach may be associated with a more favorable neurological outcome than the TF approach; hence, a systematic literature review was conducted.

Methods Between 2011 and 2017, 15 patients with PAo underwent TA-TAVI and 4 patients with PAo TF-TAVI at our institution. The assessment of PAo was done either intraoperatively after aborted sternotomy or via computed tomography for elective TAVI. We conducted mid-term follow-up. Furthermore, a systematic review was performed to compare the mortality and neurological outcomes of TF and TA-TAVI approaches.

Results TA/TF-TAVIs were performed with 100% device success, without paravalvular leakage ≥ 2 and without procedural death. The 30-day mortality/stroke rates were 6.6%/0% in TA-TAVI and 0%/25% in TF-TAVI, respectively. The 6-month, 1-year, and 2-year survival rates were in TA/TF-TAVI 93%/75%, 82%/66.6%, and 50%/0%, respectively.

The pooled results derived from the literature review were as follows: The prevalence of PAo in the TAVI population is 9.74%; the mean logistic EuroSCORE is 41.9% in TA-TAVI versus 16.2% in TF-TAVI; the mean 30-day mortality is 5.9% in TA-TAVI versus 6.3% in TF-TAVI, and the mean stroke is 0.8% in TA-TAVI versus 9% in TF-TAVI.

Conclusion TA-TAVI shows promising early and mid-term outcomes in patients with PAo. TF-TAVI performed in patients with PAo is likely to be associated with higher rates of stroke than TA-TAVI.

Intermediate Outcomes after Rapid Deployment Aortic Valve Replacement in Multiple Valve Surgery

BACKGROUND

Multiple valve surgery is associated with significant higher operative risks. Reduced cross-clamp and cardiopulmonary bypass times in multiple valve surgery may potentially be beneficial as they can be considered independent risk factors for increased morbidity and mortality following cardiac surgery. We report first intermediate outcomes of the Edwards Intuity valve system (Edwards Lifesciences, Irvine, California, United States) in combined procedures METHODS:  Fifty-eight patients underwent rapid deployment aortic valve replacement with concomitant mitral valve surgery between January 2014 and November 2017 in our institution. The valve was assessed echocardiographically after 12 months. The median follow-up was 1.7 years with a cumulative follow-up time of 115.3 patient years.

RESULTS

The mean age was 73.5 ± 6.2 years and the mean logistic Euroscore was 11.6 ± 3.1%. Concomitant mitral valve repair was performed in 43 cases (74.1%), and mitral valve replacement in 15 cases (19.0%). The mean cross-clamp time was 93 ± 21 minutes along with a mean bypass time of 118 ± 24 minutes. All-cause mortality after 30 days was 8.6%. Overall actuarial survival at 1 year was 87.2 ± 4.5% and after 2 years 82.8 ± 5.3%, respectively.

CONCLUSIONS

Rapid deployment aortic valve replacement in multiple valve surgery can be performed safely with good intermediate outcomes in elderly, high-risk patients.

Mitochondrial active and relaxed state respiration after heat shock mRNA response in the heart

Induction of Heat Shock Proteins results in cytoprotection. Beneficial effect results from transcription and translational cellular components' involvement that defends metabolism and thus induce ischemic protection of the tissue. Mitochondrial respiration is also involved in stress- induced conditions. It is not a uniform process. Cytochrome c Oxidase (CytOx) representing complex IV of the Electron Transfer Chain (ETC) has a regulatory role for mitochondrial respiratory activity, which is tested in our study after hsp induction. Moreover, protein translation for mitochondrial components was probed by the detection of MT-CO1 for Subunit 1 of CytOx neosynthesis. Wistar rats were subjected to whole-body hyperthermia at 42.0-42.5 °C for 15 min followed by a normothermic recovery period. Heat shock response was monitored time dependent from LV biopsies of all control and heat treated animals with PCR-analysis for hsp 32, 60, 70.1, 70.2, 90 and MT-CO1 expression at 15, 30, 45, 60, 120 and 360 min recovery (n = 5 in each group), respectively. Enzymatic activity of CytOx were evaluated polarographically. High energy phosphates were detected by chromatographic analysis. The mRNA expression of MT-CO1 peaked at 60 min and was accompanied by hsp 32 (r = 0.457; p = 0.037) and hsp 70.2 (r = 0.615; p = 0.003) upregulation. With hsp induction, mitochondrial respiration was increased initially. Enzymatic activity reconciled from active into relaxed status wherein CytOx activity was completely inhibited by ATP. Myocardial ATP content increased from stress induced point i.e. < 1 µmol g^-1 protein w/w to finally 1.5 ± 0.53 µmol g^-1 protein w/w at 120 min recovery interval. Hyperthermic, myocardial hsp- induction goes along with increased CytOx activity representing an increased "active" mitochondrial respiration. In parallel, de -novo holoenzyme assembly of CytOx begins as shown by MT-CO1 upregulation at 60 min recovery time crossing with a final return to the physiological "relaxed" state and ATP -inhibited respiration.

Citrulline as a Biomarker for Gastrointestinal-Acute Radiation Syndrome: Species Differences and Experimental Condition Effects

Animal models of hematopoietic and gastrointestinal acute radiation syndromes (ARS) have been characterized to develop medical countermeasures. Acute radiation-induced decrease of intestinal absorptive function has been correlated to a decrease in the number of intestinal crypt cells resulting from apoptosis and enterocyte mass reduction. Citrulline, a noncoded amino acid, is produced almost exclusively by the enterocytes of the small intestine. Citrullinemia has been identified as a simple, sensitive and suitable biomarker for radiation-induced injury associated with gastrointestinal ARS (GI-ARS). Here we discuss the effect of radiation on plasma citrulline levels in three different species, C57BL/6 mice, Göttingen minipigs and rhesus nonhuman primates (NHPs), measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). The effects of experimental study conditions such as feeding and anesthesia were also examined on plasma citrulline levels in the NHPs. Both the mice and Göttingen minipigs were partial-body irradiated (PBI) with doses from 13-17 Gy and 8-16 Gy, respectively, whereas NHPs were total-body irradiated (TBI) with doses from 6.72-13 Gy. Blood samples were taken at different time points and plasma citrulline levels were measured in the three species at baseline and after irradiation. Basal plasma citrulline concentrations (mean ± SEM) in mice and minipigs were 57.8 ± 2.8 μM and 63.1 ± 2.1 μM, respectively. NHPs showed a basal plasma citrulline concentration of 32.6 ± 0.7 μM, very similar to that of humans (∼40 μM). Plasma citrulline progressively decreased after irradiation, reaching nadir values between day 3.5 and 7. The onset of citrulline recovery was observed earlier at lower radiation doses, while only partial citrulline recovery was noted at higher radiation doses in minipigs and NHPs, complete recovery was noted in mice at all doses. Plasma citrulline levels in NHPs anesthetized with ketamine and acepromazine significantly decreased by 35.5% (P = 0.0017), compared to unanesthetized NHPs. In the postprandial state, citrulline concentrations in NHPs were slightly but significantly decreased by 12.2% (P = 0.0287). These results suggest that plasma citrulline is affected by experimental conditions such as anesthesia and feeding.

The impact of intraaortic balloon counterpulsation on bypass graft flow in patients with peripheral ECMO

OBJECTIVE

Numerous reports have been performed to investigate the hemodynamic effects of intraaortic balloon pumping (IABP) and nonpulsatile circulatory extracorporeal membrane oxygenation (ECMO), but studies on its impact on coronary artery bypass graft flow during concomitant use of IABP and ECMO are lacking. The aim of this study was to assess the impact of additional IABP support on the degree of blood flow increase in bypass grafts in high-risk patients with nonpulsatile femoral venoarterial ECMO.

METHODS

In six emergency coronary artery bypass graft patients (mean age = 66.3 +/- 2.1 years, gender = five males and one female, ejection fraction = 25.0 +/- 3.0%) requiring mechanical circulatory support with ECMO hemodynamic parameters and bypass graft flows were measured with and without IABP counterpulsation. A transit time flowmeter was used for intraoperative graft flow and pulsatility index (PI) measurements. Patients provided their control values.

RESULTS

The average value of the mean arterial pressure recorded prior to IABP was 63.6 + 2.9 mmHg and during IABP support 67.8 + 2.9 mmHg (p < 0.0001). IABP augmented the mean bypass graft flow from 46.8 +/- 9.6 mL/min to 56.4 +/- 12.1 mL/min (p < 0.005), resulting in a 17% increase. The difference in the PI was not statistically significant (2.6 +/- 0.2 with IABP, 2.6 +/- 0.3 without IABP).

CONCLUSIONS

We conclude that IABP-induced pulsatility significantly improves coronary bypass graft flows during nonpulsatile peripheral ECMO.

Temporary epicardial ventricular stimulation in patients with atrial fibrillation: acute effects of ventricular pacing site on bypass graft flows

OBJECTIVE

Data on coronary artery bypass grafts flows in patients with atrial fibrillation (AF) requiring epicardial ventricular pacing is lacking. This study aimed to evaluate the optimal epicardial ventricular pacing site in patients with AF following coronary artery bypass surgery (CABG).

METHODS

In 23 consecutive patients (mean age = 69.2 +/- 1.9 years, gender = 62% male, ejection fraction [EF]= 50.4 +/- 2.1%) monoventricular stimulations (VVI) were tested with a constant pacing rate of 100 bpm. The impact of ventricular pacing on bypass graft flow (transit-time flow probe) and pulsatility index (PI) were measured after lead placement on the mid paraseptal region of the right (RVPS) and the left (LVPS) ventricle, on the right inferior wall (RVIW), and on the right ventricular outflow tract (RVOT). In addition, hemodynamic parameters were measured. Patients served as their own control.

RESULTS

Comparison of all tested pacing locations revealed that RVOT stimulation provided the highest bypass grafts flows (59.9 +/- 6.1 mL/min) and PI (2.2 +/- 0.1) when compared with RVPS (51.3 +/- 4.7 mL/min, PI = 2.6 +/- 0.2), RVIW (54.0 +/- 5.1 mL/m; PI = 2.4 +/- 0.2), and LVPS (53.1 +/- 4.5 mL/min; PI = 2.3 +/- 0.1), respectively (p < 0.05). When analyzing patients according to their preoperative LV function (group I = EF > 50%; group II = EF < 50%), higher bypass graft flows were observed with RVOT pacing in patients with lower EF (p = n.s.).

CONCLUSIONS

Temporary RVOT pacing facilitates optimal bypass graft flows when compared with other ventricular pacing sites and should be the preferred method of temporary pacing in cardiac surgery patients with AF. Especially in patients with low EF following CABG, RVOT pacing may improve myocardial oxygen conditions for the ischemic myocardium and enhance graft patency in the early postoperative period.