Kjell Arne Rein

Transcatheter valve-in-ring implantation after failure of surgical mitral repair

OBJECTIVES Redo surgery after failed mitral valve repair may be high risk, or contraindicated in patients with comorbidities. Because of this high risk, other interventional possibilities like transcatheter valve implantation might be of benefit. We report our experience with transcatheter mitral valve-in-ring implantation (TVIR) in high-risk patients after failure of surgical ring annuloplasty. METHODS From January 2010 to February 2012, following a multidisciplinary discussion, 17 high-risk patients underwent TVIR using Edwards SAPIEN XT prostheses, via either a transvenous transseptal (n = 8), or a transapical approach (n = 9). RESULTS Patients were aged 70 ± 16 years, in New York Association classes III/IV. Their mean logistic EuroSCORE was 36 ± 17% and mean Society of Thoracic Surgeons risk score 13 ± 9%. The mean time interval between surgery and repair failure was 7 ± 3 years. Annuloplasty rings were semi-rigid in 14 cases, flexible in 2, and rigid in 1. Manufacturers ring diameters were 26 mm in 4 patients, 27 mm in 1, 28 mm in 9, 30 mm, 31 mm and 34 mm in 1. The predominant failure mode was regurgitation in 12 cases and stenosis in 5. SAPIEN XT diameters were 26 mm in 15 patients, 23 mm and 29 mm in 1. Procedural success rate was 88% (15/17). Emergency surgery was needed in 1 patient due to acute dislodgement of the ring. The degree of mitral regurgitation was reduced to none or mild in all but 2 patients; final mean gradient was 7 ± 3 mmHg. Thirty-day survival was 82% (14/17 patients). At last follow-up (13 ± 5 months), survival rate was 71% (12/17). CONCLUSIONS These preliminary results suggest that TVIR is feasible, with low operative risk, and may provide short-term clinical and haemodynamic improvement in selected high-risk patients with failure of mitral ring annuloplasty.

Exercise hemodynamics in small (≤21 mm) aortic valve prostheses assessed by Doppler echocardiography☆

Exercise Doppler echocardiography was used to assess hemodynamics in 25 patients with a < or = 21 mm aortic valve prosthesis (14 with a Medtronic-Hall 21 mm valve, three with a Medtronic-Hall 20 mm valve, three with a Sorin 21 mm valve, one with a Duromedics 21 mm valve, and four with a Carpentier-Edwards 21 mm valve). A symptom-limited upright bicycle exercise test was performed, and Doppler gradients were recorded during exercise. Gradients increased with exercise from 30 +/- 8/16 +/- 4 mm Hg (peak/mean) at rest to 46 +/- 12/24 +/- 7 mm Hg during exercise; both p < 0.001. Mean exercise gradient exceeded 30 mm Hg in five patients, and the highest mean gradient recorded was 37 mm Hg. Within the group of mechanical valves, gradients at exercise were similar for different types of valves. A linear relationship was found between gradients at rest and during exercise (peak r = 0.75, mean r = 0.77; both p < 0.001). Additional findings were midventricular velocities exceeding 1.5 m/sec in late systole in 10 patients (40%) and intraventricular flow (> or = 0.2 m/sec) toward the apex during isovolumic relaxation in 11 patients (44%). The patients with these velocity patterns had significantly smaller left ventricular cavities (end-diastolic diameter 39.8 +/- 4.8 vs 46.5 +/- 4.2 mm, p < 0.01; end-systolic diameter 24.2 +/- 3.0 vs 28.5 +/- 4.5 mm, p = 0.013).(ABSTRACT TRUNCATED AT 250 WORDS)

Time-related changes in the starling forces following extracorporeal circulation

SummaryThe intra- and postoperative variations of the transcapillary forces [colloid osmotic pressure of plasma (COPpl), colloid osmotic pressure of interstitial fluid (COPif), average hydrostatic pressure in the interstitium (Pif)] were studied in the subcutaneous tissue as a function of time in 13 patients operated on for coronary artery disease using extracorporeal circulation (ECC). The measurements were performed before operation, during ECC, and during the first 24 hours postoperatively. COPif was measured subcutaneously on the chest both by the wick method and by a noninvasive blister suction method. The latter technique allowed several consecutive measurements in the same individual during the postoperative period. Pif was measured by “wick-in-needle” technique in the same area as the COPif measurements. COPpl was measured in a blood sample collected from a cubital vein. COPpl was reduced about 50% during ECC returned to pre-ECC level within the first 6 hours postoperatively. During ECC COPif was higher than COPpl, reaching its minimum level 4 to 5 hours postoperatively. Measurements performed following ECC showed return of the transcapillary COP-gradient to the normal direction (COPpl > COPif). Pre-ECC level of COPif was not entirely obtained during the first postoperative day. Pif increased gradually during ECC and continued to increase the first 2 to 3 hours following ECC. Pre-ECC level was reached within 24 hours postoperatively. The present investigation has demonstrated major dynamic variations in the transcapillary forces in patients undergoing open heart surgery with ECC. There was an increased net capillary filtration (F) intraoperatively predisposing to interstitial edema formation in subcutaneous tissue until several hours following the termination of ECC.

Interstitial fluid colloid osmotic pressure of the subcutaneous tissue in controls and patients before and after open-heart surgery: A comparison between the wick technique and the blister suction technique

The purpose of this study was to compare the blister suction technique and the wick technique for measuring interstitial colloid osmotic pressure of subcutaneous tissue (COPif). Eight healthy volunteers and 14 patients undergoing aortocoronary bypass using extracorporal circulation (ECC) were included in the investigation. Colloid osmotic pressure was measured in fluid collected either from blisters (COPbl) developed by application of subatmospheric pressure to the chest skin, or from nylon wicks (COPw) implanted subcutaneously on the chest in the same area as the blisters were formed. Colloid osmotic pressure was then recorded on a colloid osmometer made for 5 microliter samples. In the patients, the measurements were performed 12-18 h pre-operatively (mean 15 h) and, on average, 4 h (range 1.5-7 h) following termination of extracorporal circulation. In the control subjects as well as in the patients, COPbl was significantly lower than COPw. However, the two types of measurements were found to change in the same direction, as a highly significant positive correlation exists between the two methods.

Morbidity outcomes after surgical aortic valve replacement

Objective In patients with mild to moderate operative risk, surgical aortic valve replacement (SAVR) is still the preferred treatment for patients with severe symptomatic aortic stenosis (AS). Aiming to broaden the knowledge of postsurgical outcomes, this study reports a broad set of morbidity outcomes following surgical intervention. Methods Our cohort comprised 442 patients referred for severe AS; 351 had undergone SAVR, with the remainder (91) not operated on. All patients were evaluated using the 6-minute walk test (6MWT), were assigned a New York Heart Association class (NYHA) and Canadian Cardiovascular Society class (CCS), with additional scores for health-related quality of life (HRQoL), cognitive function (Mini-Mental State Examination (MMSE)) and myocardial remodelling (at inclusion and at 1-year follow-up). Adverse events and mortality were recorded. Results Three-year survival after SAVR was 90.0%. SAVR was associated with an improved NYHA class, CCS score and HRQoL, and provoked reverse ventricular remodelling. The 6MWT decreased, while the risks of major adverse cardiovascular events (death, non-fatal stroke/transient ischaemic attack or myocardial infarction) and all-cause hospitalisation (incidence rate per 100 patient-years) were 13.5 and 62.4, respectively. The proportion of cognitive disability measured by MMSE increased after SAVR from 3.2% to 8.8% (p=0.005). Proportion of patients living independently at home, having attained NYHA class I, was met by 49.1% at 1 year. Unoperated individuals had a poor prognosis in terms of any outcome. Conclusion This study provides knowledge of outcomes beyond what is known about the mortality benefit after SAVR to provide insight into the morbidity burden of modern-day SAVR.

Transcatheter Aortic Valve Implantation and Intraoperative Left Ventricular Function: A Myocardial Tissue Doppler Imaging Study

OBJECTIVE Transcatheter aortic valve implantation in patients turned down for surgical aortic valve replacement is a high-risk procedure. Severe aortic stenosis is associated with impaired left ventricular longitudinal motion, and myocardial peak systolic velocity is a measure of left ventricular function in these patients. The present study aimed to quantify the acute changes in left ventricular function during the procedure by using myocardial tissue Doppler imaging and transthoracic cardiac output measurements. DESIGN Prospective observational study. SETTING Tertiary care university hospital. PARTICIPANTS 40 patients with severe aortic stenosis scheduled for transcatheter aortic valve implantation. INTERVENTIONS Transesophageal 4-chamber and 2-chamber echocardiograms were performed immediately before and ~15 minutes after valve implantation. Longitudinal myocardial peak systolic velocity was obtained by tissue Doppler imaging from 8 basal segments and averaged. Cardiac output was measured by the lithium dilution method, and systemic vascular resistance index and stroke volume were calculated. MEASUREMENTS AND MAIN RESULTS Longitudinal myocardial peak systolic velocity improved immediately after valve implantation, from -2.3±0.8 to -3.0±1.1 cm/sec (p<0.001); this represented an average increase of 31%±33%. Cardiac output increased from 3.2±0.8 L/min to 3.6±0.9 L/min (15%±33%; p = 0.04). This was due to increased heart rate (59±9 beats/min to 72±12 beats/min; p<0.001) and not to an improved stroke volume. Systemic vascular resistance index was reduced from 2,937±984 dynes*sec/cm(5)/m(2) to 2,436±730 dynes*sec/cm(5)/m(2) (p = 0.003). CONCLUSION Intraoperative echocardiography tissue Doppler imaging detected immediate improvement in left ventricular long-axis motion after transcatheter aortic valve implantation. The method provided detailed information not obtainable by routine hemodynamic monitoring.

Innovative technology-transcatheter aortic valve implantation: Cost and reimbursement issues

Abstract Objective. Transcatheter aortic valve implantation (TAVI) offers a new treatment option for patients with severe symptomatic aortic valve stenosis, classified as “inoperable”. The purpose of the study was to reveal the association between ascertained hospital costs with the actual patient Diagnosis-Related Group (DRG). Method. We examined 50 consecutive patients who underwent either transapical TAVI, (TAVI-TA) or transfemoral TAVI (TAVI-TF) with the Edwards SAPIEN valve and CoreValve® between September 2009 and August 2011. Results. Fourty-nine patients had successful valve deployment. Seven patients died within 30 days of the operation. The mean length of hospital stay for TAVI-TA was 199 hours (range 77–362), and the mean costs for TAVI-TA were 55,690 US

Intraoperative improvement in left ventricular peak systolic velocity predicts better short-term outcome after transcatheter aortic valve implantation

. For TAVI-TF the mean length of hospital stay was 170 hours (range 49–276) and the mean costs were 52,087 US

Clinical and echocardiographic assessment of the Medtronic ADVANTAGE aortic valve prosthesis: the Scandinavian multicentre, prospective study

. Conclusion. There was no significant difference between TAVI-TA and TAVI-TF patient characteristics. There was a significant discrepancy between actual hospital costs and the current Norwegian DRG reimbursement for the TAVI procedure. This discrepancy can be partly explained by excessive costs related to the introduction of a new program with new technology. Costly innovations should be considered in price-setting of reimbursement for novel technology.

Balloon-expandable transaortic transcatheter aortic valve implantation with or without predilation

OBJECTIVES Left ventricular function is expected to improve after transcatheter aortic valve implantation due to the acute reduction in afterload, but does not occur in all patients. We hypothesized that the immediate intraoperative response in systolic left ventricular longitudinal motion during the procedure could be a predictor of short-term outcome. METHODS Sixty-four patients treated with transcatheter aortic valve implantation for severe aortic stenosis were included. Transoesophageal 4- and 2-chamber echocardiograms were obtained immediately prior to and ∼15 min after valve implantation. Patients were defined as responders if their average left ventricular longitudinal peak systolic velocity increased by ≥20% from the preimplantation value and was related to the 3-month outcome. RESULTS Thirty-five patients were classified as responders, with an increase in the intraoperative longitudinal peak systolic velocity from an average of 2.2 ± 0.8 to 3.1 ± 1.1 cm/s (P < 0.001); the velocity was unchanged in the remaining 29 patients, who averaged 2.4 ± 1.1 cm/s. There were significantly fewer adverse cardiac events in the responder group at the 3-month follow-up (20 vs 45%, P = 0.03) and the New York Heart Association class was significantly better in the responders compared with non-responders. Responders had a significant reduction in N-terminal probrain natriuretic peptide levels [243 (113-361) vs 163 (64-273), P = 0.004] at the 3-month follow-up, whereas non-responders did not [469 (130-858) vs 289 (157-921), P = 0.48]. CONCLUSIONS An immediate improvement in the longitudinal peak systolic velocity during the transcatheter aortic valve implantation procedure predicted a better short-term outcome and may be useful in identifying patients who are at risk of a less favourable outcome after transcatheter aortic valve implantation.