Long-term outcome after coronary artery bypass grafting in patients with severe left ventricular dysfunction.

BACKGROUND: The aim of this study was to define the potential for long-term survival with severe left ventricular dysfunction after coronary bypass and to quantify any improvement in overall functional status. METHODS: Left ventricular dysfunction was confirmed preoperatively and the long-term survival and functional outcome after bypass was determined by follow-up studies obtained during the span of a decade. RESULTS: From 1/1990 to 12/1999, 86 patients with severe left ventricular dysfunction (mean ejection fraction, 0.18 +/- 0.03; range, 0.10 to 0.20) underwent coronary artery bypass grafting. There were 10 perioperative deaths (11% mortality). The mean survival was 55 months (standard deviation +/- 34 months; range, 2 to 141 months) with an actual 5-year survival rate of 59% (actuarial 5-year 65%, 10-year 33%). Echocardiography obtained between 1 and 6 months, 6 months and 1 year, 1 and 2 years, 2 and 4 years, 4 and 6 years, and 6 and 11 years showed the ejection fraction improved to 0.29 +/- 0.08 (p < 0.001), 0.31 +/- 0.14 (p < 0.002), 0.35 +/- 0.08 (p < 0.001), 0.27 +/- 0.10 (p = 0.002), 0.36 +/- 0.14 (p = 0.004), and 0.30 +/- 0.11 (p = 0.004), respectively. At 1 to 6 months, 6 months to 1 year, and 1 to 2 years, the diastolic left ventricular dimension was unchanged, but the systolic left ventricular dimension decreased significantly from 5.02 +/- 0.77 cm to 4.26 +/- 0.91 cm (p = 0.046), 3.98 +/- 1.43 cm (p = 0.08), and 4.10 +/- 1.14 cm (p = 0.07). The preoperative New York Heart Association classification for all patients improved from 2.8 +/- 0.8 to 1.6 +/- 0.7 (p < 0.001) after a mean of 53 months (standard deviation +/- 34 months). CONCLUSIONS: Patients with severe left ventricular dysfunction can derive long-term benefit from coronary bypass through improved left ventricular contractility as documented by a significantly decreased systolic left ventricular dimension and increased ejection fraction. Successful bypass is associated with a 59% actual 5-year survival rate and significantly improved New York Heart Association functional class.

Serial Doppler Gradients Are Predictive of Future Bioprosthetic Valve Degeneration.

Doppler echocardiography and color flow imaging are helpful techniques in evaluating the functional status of a bioprosthetic valve. The aim of this study was to determine whether serial Doppler gradients are predictive of future bioprosthetic valve degeneration. We performed serial echo-Doppler studies over a 6-year period (1988-1994) on 228 patients who had undergone mitral (n = 112) or aortic (n = 116) bioprosthetic valve implantation between 1973 and 1994. Thirty-nine mitral prostheses and 30 aortic prostheses became dysfunctional and required reoperation. A serial rise in mean gradient of 5 mmHg or more across the mitral valve and 25 mmHg or more across the aortic valve was significantly associated with increased valve degeneration (odds ratio 3.40 and 16.11 and 95% confidence intervals 1.31 and 8.80 and 13.6 and 72.13 for the mitral and aortic valve, respectively). Both aortic and mitral valves began to degenerate after 8 years. Serial echo-Doppler studies showed a rise in transvalvular gradients around the same time. Closer evaluation for prosthetic valve dysfunction should be considered in patients 8 or more years status post surgery, especially those with high transvalvular gradients.