Does perioperative Atenolol reduce mortality and/or cardiovascular events in patients with CAD or risk factors for CAD who are undergoing noncardiac surgery?

Maria Jison MD
10/2/97


Methods

*Randomized, double blinded with placebo controls.
*200 patients undergoing noncardiac surgery requiring general anesthesia who either had CAD or at least 2 risk factors for CAD.
*Preoperative medications were continued in all patients up to the time of surgery.
*Patients were given Atenolol or Placebo before and after surgery and daily thereafter for the length of hospital stay up to one week.
*192 patients followed at 6mo, lyr and 2yr.
*Primary outcome was death from all causes.
*Secondary outcome was combined MI, unstable angina, CHF requiring hospitalization and need for coronaryrevascularization procedures.


Data

  Atenolol n=99 Placebo n=101 p value RR Reduction ARR NNT
Prior to Discharge            
Total Deaths 2 1        
Cardiac Deaths 1 2   50% 1% 100
Total Deaths @ 6 mos 1 10 <0.001 90% 9% 11
Cardiac 0 7        
Noncardiac 1 3        
Total Deaths @ 1 yr 3 14 0.005      
Total Deaths @ 2 yr 9 21 0.02 57% 12% 8
Cardiac 4 12 0.033 67% 8% 12
Combined Cardiac events (MI, Unst Ang, CHF)            
6 mo 0 12 <0.001 100% 12% 8
1 yr 7 22 0.003 69% 15% 7
2 yr 16 32 0.008 50% 16% 6


Conclusion
Perioperative Atenolol in patients with CAD or at risk for CAD reduced the risk of death and cardiac events.


Comments


*Characteristics of both groups were fairly similar except that more patients in the Atenolol group were being treated for their HTN with B-blockers, diuretics, CCB, and ACE-I were not mentioned. Prior RX with antihypertensives, particularlyACE-I, can have long term mortality benefits that can confound results.
*Whether patients continued to receive Atenolol after discharge or whether they were treated with meds which can affect mortality after discharge was not discussed.
*Sex of patients not specified and whether or not postmenopausal women were undergoing HRT.
*Effects on absolute risk reduction not seen in perioperative period, and NNT much higher for periop.
*Small sample size.
*Seems like this is a pretty good study but would be more convincing if other variables mentioned above were controlled.

Reference
Mangano DT, Layug EL, Wallace A, Tateo I. Effect of Atenolol on Mortality and Cardiovascular Morbidity After Noncardiac Surgery. N Engl J Med. 1996;335:1713-19.