Preoperative risk models for minimally invasive coronary bypass: a preliminary study.
OBJECTIVE
Available risk assessment models are designed for standard coronary artery bypass grafting. We hypothesized that minimally invasive coronary bypass could improve on predicted outcome in extremely high-risk patients (Parsonnet score > 20%) by the current risk models.


METHODS
From September 1996 to September 1997, 27 consecutive extremely high-risk patients underwent minimally invasive coronary bypass. Seventeen patients were male; age was 73 +/- 12 years, and 63% of patients were older than 75 years. Left ventricular ejection fraction was 33.7% +/- 15% and 63% had an ejection fraction of less than 35%. The predicted 30-day mortality according to the System 97 model was 25.6% +/- 11.3%. The Parsonnet risk score was 36.2% +/- 11%; the predicted length of stay in the hospital was 15.3 +/- 3 days. The predicted risk of stroke according to the Multicenter Perioperative Stroke Risk Index was 22.3% +/- 11.7%.


RESULTS
Minimally invasive coronary bypass was isolated in 20 patients and integrated with angioplasty and stenting in 7 patients. The observed 30-day mortality was 0% (P < .01 vs predicted): at an average follow-up of 10.8 +/- 4.1 months, 26 patients (96.3%) are alive without angina; one patient with acquired immunodeficiency syndrome died on postoperative day 40 of acute pancreatitis. No patient had a stroke or neurologic deficit (P < .01 vs predicted). Patency of internal thoracic artery anastomosis was confirmed by angiography in all 27 patients. No patient required reoperation. Eighteen patients (67%) were extubated in the operating room. The observed length of hospital stay after minimally invasive coronary bypass was 3.8 +/- 2.6 days (P < .01 vs predicted).


CONCLUSIONS
On the basis of our results on a relatively small series of patients, we suggest that risk models geared for standard coronary bypass grafting may not be appropriate for minimally invasive coronary bypass.
Division of Cardiothoracic Surgery, University of Pittsburgh Medical Center, PA 15213-2582, USA.
M
M
Zenati
H A
HA
Cohen
R
R
Holubkov
A J
AJ
Smith
A J
AJ
Boujoukos
J
J
Caldwell
L
L
Firestone
B P
BP
Griffith
D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000401:mortality; D002423:Cause of Death; D002561:Cerebrovascular Disorders / Q000401:mortality; D003131:Combined Modality Therapy; D001026:Coronary Artery Bypass / Q000401:mortality*; D003327:Coronary Disease / Q000401:mortality / Q000601:surgery*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000401:mortality*; D011183:Postoperative Complications / Q000401:mortality*; D018570:Risk Assessment; D015607:Stents / Q000706:statistics & numerical data; D016896:Treatment Outcome