Mitroflow aortic pericardial bioprosthesis--clinical performance.

OBJECTIVE: Advancing life expectancy with the increased prevalence of aortic valve degenerative disease brings the need for an aortic bioprosthesis with excellent haemodynamic performance and comparable durability. The Mitroflow bioprosthesis has been on the worldwide market, except in the United States, since 1982, while the current model (1991) has only recently gained regulatory approval in the latter country. This study was primarily performed to determine the durability of the current Mitroflow bioprosthesis. METHODS: The contemporary Mitroflow bioprosthesis was implanted in 381 patients in three centres. The mean age was 76.4 years (range 53-91 years) and the mean follow-up period was 5.4+/-3.4 years, a total of 2048.7 years of evaluation. Prosthesis-patient mismatch (PPM) was classified by reference effective orifice area index categories: normal > or = 0.85 cm(2) m(-2) (53.9%), mild 0.84-0.76 cm(2) m(-2) (33.9%), moderate < or = 0.75-0.66 cm(2) m(-2) (11.7%) and severe < or = 0.65 cm(2) m(-2) (0.5%). RESULTS: The survival, at 10 years, was 39.9+/-7.9% for 50-69 years, 27.0+/-3.7% for 70-79 years and 16.6+/-4.4% for > or = 80 years (p=0.011). There was a trend (p=0.063) influencing survival for moderate-to-severe PPM. Of the independent predictors influencing survival--moderate-to-severe projected effective orifice area index (pEOAI) (Hazard Ratio (HR) 1.6, p=0.0142) and left ventricular dysfunction (ejection fraction < 35%) (HR 1.9, p=0.0193) were included. The 10-year freedom from structural valve deterioration (SVD) at explant assessing the same age groups as survival was not different (p=0.081). The 10-year actual/actuarial freedom from SVD, at explant was for > or = 60 years--94.4+/-1.4% (85.2+/-3.9%), for > or = 65 years--94.2+/-1.4% (85.0+/-4.0%), for 61-70 years--97.4+/-2.6% (95.7+/-4.3%) and for > 70 years--94.0+/-1.5% (83.2+/-4.6%). CONCLUSIONS: The Mitroflow external mounted, pericardial aortic bioprosthesis with documented excellent haemodynamics (especially for the small aortic root), demonstrates that prosthesis-patient mismatch in moderate and severe categories can essentially be eliminated, with durability performance comparable to other heterograft (porcine and pericardial) bioprostheses.

Changing outcomes of coronary revascularization in British Columbia, 1995-2001.

OBJECTIVES: To examine outcomes following all first coronary revascularization procedures, isolated coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) on British Columbia (BC) resident adults from 1995 to 2001. METHODS: CABG and PCI data were obtained from the BC Cardiac Registry, and mortality data were obtained from the BC Vital Statistics Agency. Analysis was performed by annual cohorts, and the rates reported are unadjusted. RESULTS: An increasing percentage of revascularization procedures was performed with PCI (62% in 1995 to 73% in 2001; P<0.001) due to the increased use of PCI procedures. Except in emergent cases, 30-day mortality improved after PCI (1.8% to 1.1%; P=0.02) and CABG (1.8% to 1.2%; P=0.01). Emergent cases accounted for 9.0% of PCIs and 2.7% of CABGs, the percentage treated by CABG decreasing from 14.5% in 1995 to 7.5% by 2001 (P<0.001). Mortality rates among emergent cases was higher at 30 days, with no trend in PCI mortality (12%) but a substantial reduction in 30-day mortality after CABG (28% to 10%; P=0.003). One-year survival free from repeat revascularization following PCI increased from 73% in 1995 to 83% in 2001 (P<0.001) and from 94% to 95% (P<0.005) following CABG. CONCLUSIONS: Improvements in procedure-related mortality observed in trials have extended to clinical practice. With respect to emergent cases, an increasing proportion were treated by PCI with no change in PCI mortality but associated with a drop in surgical mortality. There has been a consistent and substantial drop in the need for repeat procedures within one year for patients selected for PCI.

Use of physiologic pacing after the Canadian trial of physiologic pacing.

The Canadian trial of physiologic pacing (CTOPP), published in 2000, demonstrated a reduction in atrial fibrillation (AF), stroke and death with preservation of atrioventricular synchrony, though only the lower rate of AF was statistically significant. The purpose of this study was to determine the effect of CTOPP on pacing mode selection in our region. The British Columbia Cardiac Registry contains prospectively entered data covering a population of 4 millions (M) and 17 implanting centers. It was examined for mode selection trends from 1997 to 2002. At examination, there were data on 22,446 pulse generators (PG) and 29,898 leads. New implant rates per M population were 1997:473; 1998:456; 1999:505; 2000:513; 2001:486; 2002:510. PG replacements also increased, resulting in a total implant rate of 667 PG per M in 2002. Over the 6-year period, DDD use decreased from 321 to 306, but DDDR use, more than doubled from 317 to 750 PG/year. VVI use steadily decreased from 741 to 410 PG/year, while VVIR use increased more modestly from 1997 to 1999, then remained stable. During the 6-year period bracketing CTOPP, use of modes maintaining AV synchrony increased by over 32%, to 53% of PG implanted in 2002. Our PG implant rate was much higher than expected from prior retrospective surveys, and similar to rates in Belgium, France, and Germany. CTOPP did not decrease our use of physiologic pacing but, instead, was associated with a brief pause, then progressively increased in both academic and community centers. Patients' need and widely accepted standards of care proved more important in clinical decision making than the results of a flawed randomized trial.