Paul C. Cartier

Patient-prosthesis mismatch can be predicted at the time of operation

BACKGROUND Patient-prosthesis mismatch is a frequent cause of high postoperative gradients in normally functioning prostheses. The objective of this study was to determine whether mismatch can be predicted at the time of operation. METHODS Indices used to predict mismatch were valve size, indexed internal geometric area, and projected indexed effective orifice area (EOA) calculated at the time of operation, and results were compared with indexed EOA and mean gradients measured by Doppler echocardiography after operation in 396 patients. RESULTS The sensitivity and specificity of these indices to detect mismatch, defined as a postoperative indexed EOA of 0.85 cm2/m2 or less, were respectively: 35% and 84% for valve size, 46% and 85% for indexed internal geometric area, and 73% and 80% for projected indexed EOA. Projected indexed EOA also correlated best with resting (r = 0.67) and exercise (r = 0.77) postoperative gradients. CONCLUSIONS The projected indexed EOA calculated at the time of operation accurately predicts mismatch as well as resting and exercise postoperative gradients, whereas valve size and indexed internal geometric area cannot be used for this purpose.

Hemodynamic and physical performance during maximal exercise in patients with an aortic bioprosthetic valve: comparison of stentless versus stented bioprostheses.

OBJECTIVES The objective of this study was to compare stentless bioprostheses with stented bioprostheses with regard to their hemodynamic behavior during exercise. BACKGROUND Stentless aortic bioprostheses have better hemodynamic performances at rest than stented bioprostheses, but very few comparisons were performed during exercise. METHODS Thirty-eight patients with normally functioning stentless (n = 19) or stented (n = 19) bioprostheses were submitted to a maximal ramp upright bicycle exercise test. Valve effective orifice area and mean transvalvular pressure gradient at rest and during peak exercise were successfully measured using Doppler echocardiography in 30 of the 38 patients. RESULTS At peak exercise, the mean gradient increased significantly less in stentless than in stented bioprostheses (+5 +/- 3 vs. +12 +/- 8 mm Hg; p = 0.002) despite similar increases in mean flow rates (+137 +/- 58 vs. +125 +/- 65 ml/s; p = 0.58); valve area also increased but with no significant difference between groups. Despite this hemodynamic difference, exercise capacity was not significantly different, but left ventricular (LV) mass and function were closer to normal in stentless bioprostheses. Overall, there was a strong inverse relation between the mean gradient during peak exercise and the indexed valve area at rest (r = 0.90). CONCLUSIONS Hemodynamics during exercise are better in stentless than stented bioprostheses due to the larger resting indexed valve area of stentless bioprostheses. This is associated with beneficial effects with regard to LV mass and function. The relation found between the resting indexed valve area and the gradient during exercise can be used to project the hemodynamic behavior of these bioprostheses at the time of operation. It should thus be useful to select the optimal prosthesis given the patients body surface area and level of physical activity.

Hemodynamic Performance During Maximum Exercise in Adult Patients With the Ross Operation and Comparison With Normal Controls and Patients With Aortic Bioprostheses

This study examines the resting and exercise hemodynamic performance of the pulmonary autografts in the aortic position as well as of the homografts used for right ventricular outflow reconstruction in patients undergoing the Ross operation. Previous studies have reported excellent resting hemodynamics in patients who underwent aortic valve replacement with a pulmonary autograft. However, there are very few studies of their hemodynamic performance during exercise. Twenty adult subjects who underwent the Ross operation and 12 normal control subjects were submitted to maximum romp bicycle exercise. The valve effective orifice areas and transvalvular gradients of both aortic (autograft) and pulmonary (homograft) valves were measured at rest and at peak of maximum exercise using Doppler echocardiography. Valve areas were indexed for body surface area. The hemodynamics of the aortic valve were very similar in Ross subjects and in control subjects at rest and during exercise. However, the indexed valve area of the pulmonary valve at rest was significantly (p < 0.001) lower in the Ross subjects (1.10 +/- 0.46 cm2/ m2) than in the control subjects (1.95 +/- 0.41 cm2/m2), resulting in higher (p = 0.004) mean gradients at rest (Ross: 9 +/- 7 mm Hg vs control: 2 +/- 1 mm Hg) and at peak exercise (Ross: 21 +/- 14 mm Hg vs control: 7 +/- 2 mm Hg). The pulmonary autograft provided excellent hemodynamics in the aortic position either at rest or during maximum exercise, whereas moderately high gradients were found during exercise across the homograft implanted in the pulmonary valve position. Future improvement of the Ross procedure should be oriented toward the search of new methods to prevent the deterioration of the homografts.

Pacemaker contact sensitivity: case report and review of the literature.

DÉRY, J.‐P., et al.: Pacemaker Contact Sensitivity: Case Report and Review of the Literature. Pacemaker contact sensitivity is a rare condition. Less than 25 reports of pacemaker skin reaction have been described over the past 30 years. This report describes one patient who developed contact dermatitis after implantation of two subsequent pacemakers. The diagnosis was made with skin patch tests that were positive to polyurethane 75D and polysulfone beige, two of the pacemaker and connector components. Review of the literature and general guidelines for the management of this unusual condition is depicted in this report.

Changes in Left Ventricular Mass and Function After Aortic Valve Replacement: A Comparison Between Stentless and Stented Bioprosthetic Valves

The objective of this study was to compare stentless bioprostheses with stented bioprostheses with regard to the postoperative changes in left ventricular (LV) mass and function. Forty patients with aortic stenosis undergoing valve replacement with a stentless (20 patients) or a stented (20 patients) bioprosthesis were evaluated early (baseline), 1 year, and 2 years after operation. Left ventricular mass index was calculated with the corrected American Society of Echocardiography formula. The relative changes between end-diastole and end-systole in LV mid-wall radius, length, and volume (ejection fraction) were determined with a previously validated model for dynamic geometry of the left ventricle. Overall, a significant decrease was found in LV mass index (from 155 +/- 30 to 112 +/- 23 g/m(2); P <.001) and a significant increase in longitudinal shortening (from 0.12 +/- 0.11 to 0.22 +/- 0.08; P <. 001), and ejection fractions (from 0.67 +/- 0.11 to 0.71 +/- 0.10; P =.017). No significant change was found in the mid-wall radius shortening fraction. Two years after surgery, the extent of LV mass regression was greater in stentless bioprostheses (-51 +/- 18 vs -35 +/- 17 g/m(2); P =.01), though the average mass index was similar in both groups (114 +/- 26 vs 110 +/- 20 g/m(2)). Also at 2 years, the longitudinal shortening fraction was greater in patients with a stentless bioprosthesis (0.25 +/- 0.07 vs 0.18 +/- 0.08; P =.03). In conclusion, this study suggests that the superior hemodynamic performance of stentless bioprostheses may have some benefits with regard to LV mass regression and function after aortic valve replacement. The significance of these benefits in terms of prognosis remains to be determined.

Mosaic valve international clinical trial: early performance results

BACKGROUND A new third generation porcine bioprosthesis was developed in an attempt to improve on hemodynamic performance and durability of current prostheses. METHODS One thousand, two hundred, sixty patients underwent aortic valve replacement and 366 patients underwent mitral valve replacement between February 1994 and September 2000. The cumulative follow-up was 3,696.3 patient-years for aortic valve replacement and 880.1 patient-years for mitral valve replacement. Follow-up was complete for 95.5% of aortic valve replacement patients and 97.5% of mitral valve replacement patients. RESULTS For aortic valve replacement, freedom from valve-related adverse events at 1 year was 96.5%+/-0.5% for antithromboembolic-related hemorrhage and 100% for structural valve deterioration. Freedom from valve-related adverse events at 5 years was 93.8%+/-2.6% for antithromboembolic-related hemorrhage and 99.3%+/-0.9% for structural valve deterioration. For mitral valve replacement, freedom from valve-related adverse events at 1 year was 96.0%+/-1.1% for antithromboembolic-related hemorrhage and 100% for structural valve deterioration. Freedom from valve-related adverse events at 4 years was 92.1%+/-3.7% for antithromboembolic-related hemorrhage and 100% for structural valve deterioration. CONCLUSIONS These results support the claim that the Mosaic bioprosthetic valve is efficacious and safe, but continued follow-up is mandatory to determine mid- and long-term performance.

Medtronic intact porcine bioprosthesis experience to twelve years

BACKGROUND The Medtronic Intact porcine bioprosthesis was further evaluated to determine the influence of zero-pressure glutaraldehyde fixation on structural valve deterioration (SVD). METHODS From 1986 through 1996, at three Canadian centers, 1,272 patients had 1,296 procedures: 836 aortic valve replacement (AVR), 332 mitral valve replacement (MVR), 14 tricuspid valve replacement, 3 pulmonary valve replacement, and 111 multiple valve replacements. The mean age of the patient population was 67 years (range 9 to 91 years). The total follow-up was 8,011 patient-years (mean 6.2 years). RESULTS The late mortality (overall) was 4.8% and 6.7% per patient-year for AVR with or without concomitant procedures, respectively; and 4.7% and 10.4% per patient-year for MVR, respectively. There were 51 cases of SVD (AVR 22 of 836; MVR 23 of 332; pulmonary valve replacement 1 of 3; and multiple valve replacement 5 of 111). The actuarial freedom from SVD at 12 years for AVR was 94.3%+/-3.3% for patients aged 61 to 70 years and 97.7%+/-1.1% for those more than 70 years; for MVR actuarial freedom from SVD at 12 years was 93.7%+/-3.9% for patients more than 70 years. The actual freedom at 12 years from SVD for AVR was 92.4%+/-3.1% for patients aged 51 to 60 years, 96.1%+/-2.1% for those 61 to 70 years, and 98.4%+/-0.7% for those older than 70 years; for MVR actual freedom from SVD at 12 years was 89.6%+/-3.2% for patients 61 to 70 years and 96.6%+/-3.4% for those more than 70 years. CONCLUSIONS The Medtronic Intact porcine bioprosthesis, formulated with tissue preservation at zero-pressure fixation, has encouraging freedom from structural failure.

Medtronic intact porcine bioprosthesis: 10 years’ experience

BACKGROUND The Medtronic Intact porcine bioprosthesis experience was evaluated over a period of 10 years to determine the influence of structural valve deterioration by valve position in various age groupings. METHODS From 1986 to 1996 inclusive, at three centers, 1,272 patients had the prosthesis implanted in 1,296 procedures. The mean age of the population was 67 years (range, 9 to 91 years). There were 836 aortic valve replacements (AVR) (64.5%), 333 mitral valve replacements (MVR) (25.7%), and 110 multiple valve replacements (MR) (8.5%). RESULTS The early mortality was 7.3% (94 of 1,296 procedures). The early mortality with concomitant procedures (primarily coronary artery bypass grafting) was 9.8% (52 of 528) and without, 5.5% (42 of 768). The late mortality was 4.25%/patient-year. The linearized rate of major thromboembolism was 0.86%/patient-year. The rate of reoperation was 1.19%/patient-year and valve-related mortality, 1.06%/patient-year. There were 36 cases of structural valve deterioration for aortic valve replacement (16), mitral valve replacement (15), tricuspid valve replacement (2), and multiple valve replacement (3). The freedom from structural valve deterioration for aortic valve replacement was in patients 21 to 40 years, 62.5%+/-25.8% at 7 years; 41 to 50 years, 75.0%+/-15.3% at 7 years; 51 to 60 years, 91.0%+/-4.5% at 8 years; 61 to 70 years, 98.7%+/-0.7% at 10 years; and older than 70 years, 98.3%+/-1.0% at 10 years (p < 0.05). The freedom from structural valve deterioration for mitral valve replacement was for patients 41 to 50 years, 91.7%+/-8.0% at 7 years; 51 to 60 years, 85.9%+/-9.9% at 8 years; 61 to 70 years, 86.3%+/-6.8% at 8 years; and older than 70 years, 93.9%+/-4.8% at 8 years (not significant). CONCLUSIONS The Medtronic Intact porcine bioprosthesis has acceptable freedom from structural valve deterioration in both the aortic and mitral positions approaching 10 years of evaluation.

Lobectomy in the treatment of the scimitar syndrome.

The scimitar syndrome is a congenital anomaly that consists mainly of total or partial anomalous venous drainage of the right lung to the inferior vena cava. We report the case of an 8-year-old girl diagnosed at birth as having a scimitar syndrome and who presented with recurrent right lower lung infections. She underwent resection of the lower half of her right lung without diversion of the anomalous venous drainage of the upper portion of the lung. She improved rapidly postoperatively and the shunt fraction diminished.

Medtronic intact porcine bioprosthesis: Clinical performance to seven years

The clinical performance of the Medtronic Intact porcine bioprosthesis was evaluated in 1,084 patients (mean age 66.4 years, range 9 to 91 years) who had a total of 1,099 implantations between 1985 and 1992, inclusive. There were 709 aortic valve replacements, 297 mitral valve replacements, and 80 multiple valve replacements. Concomitant procedures were performed in 432 (39.3%). The age group distribution (years) was 35 or younger in 20 patients, 36 to 50 in 64, 51 to 64 in 274, 65 to 69 in 225, 70 or older in 500. The total follow-up time was 2,741 patient-years (mean, 2.5 years) and was 97.5% complete. The early mortality rate was 7.1% and late mortality was 3.9% per patient-year. The overall patient survival at 7 years was 70% +/- 3%. The freedom from major thromboembolism was 94% +/- 1% at 7 years (p = not significant for valve positions). The freedom from reoperation at 7 years was 93% +/- 1%; freedom from valve-related mortality was 89% +/- 2%. The freedom from structural valve deterioration at 7 years was 97% +/- 1% (aortic valve replacement 97% +/- 1%; mitral valve replacement 97% +/- 2%). The freedom from structural valve deterioration among age groups was not different for the overall population, aortic valve replacement, or mitral valve replacement. Hemodynamic assessment revealed obstructive properties for aortic valve replacement sizes of 21 and 23 mm and for mitral valve replacement sizes of 25 and 27 mm.(ABSTRACT TRUNCATED AT 250 WORDS)