Heart Care News You Can Use:




Topic of the Month: Preoperative Risk Assessment and Risk Reduction Before Surgery

Every time we do surgery or an intervention there is risk involved. It is important to measure
each individual's risk before any surgery and reduce risk to a minimum because the operating
room is a bad place for surprises. Perioperative myocardial infarction, which is a heart attack
around the time of the surgery, is the main cause of morbidity and mortality (complications
and death) in patients undergoing non-cardiac surgery. Perioperative management aims
at optimizing the patient's condition by identifying underlying cardiac risk factors and
diseases. During surgery the patient might be susceptible to prolong myocardial ischemia,
which is decreased oxygen supply to the heart do to the stress of the surgery in the presence
of significant narrowing of the coronary arteries. This will lead to subendocardial ischemia
(decreased blood flow to the inner area of the heart muscle) or may lead to coronary occlusion
after a plaque rupture with subsequent blood clot formation.

Systemic medical therapy prior to surgery aims to prevent mismatch of myocardial oxygen
supply and demand and to stabilize coronary plaques to reduce the risk of perioperative
myocardial infarction. Medications called beta-blockers, statins and aspirin are widely
used for this purpose in this setting.

Around the time of surgery patients should change their life-style and medical therapy to
lessen the impact of cardiovascular risk factors, as the patient should live long enough
after the operation to enjoy the benefit of the surgery. Predictors of major cardiovascular
complications include:

1. Surgery lasting more than one hour in duration.
2. Ischemic heart disease, such as coronary arteriosclerosis, myocardial infarction,
  or poor circulation to the lower extremities.
3. Congestive heart failure where the body starts to fill up with an extra amount of fluid.
4. Previous stroke or CVA (cerebro-vascular accident).
5. Insulin-dependent diabetes mellitus.
6. Renal failure.

Depending on the presence of one or more of these factors, we can predict the rate of major
cardiac complication after surgery. Complication risk is less than 0.4% if none of these
factors are present and 0.9%, 7%, and 11% if one, two or three factors are present respectively.
The use of beta-blockers was associated with a significant decrease in the size of the atheroma
(cholesterol build-up) in the artery. Highly selective beta 1-blockers are most recommended
and long acting beta-blockers are better than short-acting ones.

Cholesterol lowering agents called statins have demonstrated to decrease lipid, lipid
oxidation, inflammation, and cell death. These properties of statins may stabilize coronary
plaques thereby preventing their rupture and subsequent myocardial infarction in the perioperative
period. Side effect such as statin-induced myopathy (muscle damage) and rhabdomyolysis (muscle
destruction) are a major concern, but the potential benefit of perioperative statin therapy
appeared to outweigh the risk of potential hazard. Therapy should be initiated a few days before
surgery in combination with dose adjustment for tight heart rate control. It is strongly advised
to continue the beta-blocker therapy throughout the perioperative period. Additionally, there is
benefit in the long run for continuation of beta-blocker use, even up to 30 months after surgery.


Topic 1 - Aspirin To Prevent Heart Attack And Stroke
Topic 2 - Preoperative Risk Assessment and Risk Reduction Before Surgery

Address: 659 W. Hamilton Avenue | Eau Claire | WI 54701  | Tel: (715) 831 4444 | Regular hours: 8a.m. - 5 p.m. (Monday - Friday)