Patients undergoing infrainguinal bypass to treat atherosclerotic vascular disease are underprescribed cardioprotective medications: effect on graft patency, limb salvage, and mortality.
BACKGROUND
Established American Heart Association guidelines recommend the use of statin drugs, angiotensin converting enzyme (ACE) inhibitors, and antiplatelet agents in patients with systemic atherosclerosis, such as those undergoing operative intervention to treat peripheral atherosclerotic disease. Many of these patients have not received treatment of coronary heart disease and have not been prescribed these medications. Whether statin drugs and ACE inhibitors confer an improvement in graft patency, limb salvage, and operative mortality is unknown.


METHODS
Consecutive patients who underwent infrainguinal bypass between 1997 and 2002 were evaluated for demographic data, comorbid disease, medication use, as well as cumulative graft patency, limb salvage, and mortality. Univariate, multivariate logistical regression, and Kaplan-Meier analyses were performed. P <.05 was considered significant.


RESULTS
Two hundred ninety-three patients (mean age, 64 years; 67% men) underwent 338 infrainguinal bypass procedures with autologous vein (n = 218), prosthetic grafts (n = 88), or composite prosthetic-vein grafts (n = 32). Limb salvage was the operative indication in 75% of procedures. Coexisting diseases included hypertension (70%), diabetes (52%), hyperlipidemia (37%), coronary heart disease (51%), congestive heart failure (14%), and active tobacco use (30%). Statin drugs were taken by 56% of patients, ACE inhibitors by 54% of patients, and antiplatelet agents or warfarin sodium (Coumadin) by 93% of patients. Postoperative graft surveillance was done in 39% of patients. Cumulative graft patency was 73%, limb salvage was 85%, and mortality was 9%, with a mean follow-up of 17 months. Factors independently associated with increased graft patency included statin drug use (odds ratio [OR], 3.7; 95% confidence interval [CI], 2.1-6.4), male sex (OR, 2.8; 95% CI, 1.6-5.0), and graft surveillance (OR, 2.4; 95% CI, 1.3-4.5). Factors associated with decreased amputation rate were statin drug use (OR, 0.34; 95% CI, 6.15-0.77) and graft surveillance (OR, 0.23; 95% CI, 6.1-0.63). Factors associated with decreased mortality included graft surveillance (OR, 0.18; 95% CI, 0.1-0.56), whereas congestive heart failure (OR, 6.5; 95% CI, 2.5-17) and hemodialysis-dependent renal failure (OR, 29; 95% CI, 6.1-140) were associated with increased mortality. Kaplan-Meier analysis showed that only ACE inhibitors were associated with lower mortality (P =.05)


CONCLUSIONS
Patients undergoing infrainguinal bypass are undertreated with respect to cardioprotective medications. ACE inhibitor use is associated with lower mortality, and statin drug use is associated with improved graft patency and limb salvage. Institution of consensus guidelines concerning these medications should be considered by all vascular specialists, including vascular surgeons.
Henke
Peter K
PK
Cardiovascular Division of Medicine, University of Michigan, Ann Arbor, MI, USA. henke@umich.edu
Blackburn
Susan
S
Proctor
Mary C
MC
Stevens
Jeri
J
Mukherjee
Debabrata
D
Rajagopalin
Sanjay
S
Upchurch
Gilbert R
GR
Stanley
James C
JC
Eagle
Kim A
KA
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D001161:Arteriosclerosis / Q000188:drug therapy* / Q000401:mortality / Q000601:surgery*; D001166:Arteriovenous Shunt, Surgical; D001807:Blood Vessel Prosthesis; D002316:Cardiotonic Agents / Q000627:therapeutic use*; D015897:Comorbidity; D004363:Drug Utilization; D005260:Female; D005500:Follow-Up Studies; D019983:Guideline Adherence; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D015993:Life Tables; D023821:Limb Salvage; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016491:Peripheral Vascular Diseases / Q000188:drug therapy* / Q000401:mortality / Q000601:surgery*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012501:Saphenous Vein / Q000601:surgery; D016019:Survival Analysis; D013997:Time Factors; D014654:Vascular Patency
D000806:Angiotensin-Converting Enzyme Inhibitors; D002316:Cardiotonic Agents; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010975:Platelet Aggregation Inhibitors