Preoperative Cardiac Evaluation Quiz Answers
1. 52 y/o male PMH sign for DM, CAD (s/p stent 1 year ago) presents for "clearance" for right total knee replacement. He is unable to climb one flight of stairs without stopping. Surgery is scheduled for the next day. *Patients Revised Cardiac Risk Score is 1.
Patient should proceed with the planned surgery with metoprolol added day of surgery.
Preoperative cath would be recommended for this patient.
Answer: Surgery should be delayed while metoprolol is added and titrated up for goal HR control of 60.
Discussion: This patient is considered higher risk due to his CAD and DM. His revised cardiac risk index is 2 due to his DM and CAD. No comment is made on whether he is on insulin, but the 2007 guidelines changed that criteria from the risk score. This is based upon data showing increased risk if insulin is used perioperatively. Since almost all diabetics will receive insulin perioperatively (SSI), it was felt the scoring system was misleading. With a RCRI of 2, he has a 6.6% chance of a perioperative cardiac event. The patient is also unable to achieve 4 METS, based upon his inability to climb one flight of stairs without stopping. This can be estimated (Estimating METS). Keep in mind that the patient may answer using his activity level up to 6 months ago, assuming he is unlikely to be able to climb a flight of stairs at this time due his knee.
With this information, it would be recommended that patient should achieve heart control. Beta blockers have been shown to be beneficial, preventing perioperative cardiac events. A recent study (POISE) demonstrated an increase risk of CVA though. It is felt this is related to starting the beta blocker too soon prior to surgery. During surgery, the mean arterial pressure (MAP) is often permitted to drop by 20%. If a beta-blocker has recently been added, this drop in MAP may actually be much greater compared to their typical baseline due to the drop in bp from the beta blocker plus the permitted drop in the OR. It is felt that two weeks is necessary (some say 1 week) for the brain to adjust to the new baseline blood pressure. For this reason, patients should wait at least 2 weeks prior to surgery once the beta-blocker has been titrated up to goal.
Utilizing the algorithm:
1. Not an emergent surgery
2. No active cardiac problems
3. This is not a low risk surgery
4. Unable to achieve 4 METS or more.
5. He has only 2 risk factors: Heart rate control would be recommended.
2. 78 y/o male with PMH sign for CAD, DM, CHF, COPD presents for "clearance" for cataracts surgery tomorrow. *
Lipitor has been shown to reduce cardiac events in this clinical situation.
Patient should have a stress test prior to surgery.
Surgery should be delayed while metoprolol is added and titrated up to a goal HR of 60.
Answer: Patient should proceed to planned event without any further intervention.
Discussion: Not surprisingly, low risk procedures are low risk! A study from 1993 demonstrated a protective effect of ophthalmic procedures! Reviewing morbidity and mortality data, it showed that patients were less likely to have cardiac events when undergoing ophthalmic procedures. This was felt to be related to patients actually being monitored and optimized. With this knowledge, patients do not need any evaluation for low risk procedures. They are less likely to have any events during that time period!
Utilizing the algorithm:
1. Not an emergent surgery
2. No active cardiac problems
3. This is a low risk surgery: Proceed with surgery.
3.88 y/o male PMH CAD, DM, HTN, CHF presents to ED after falling. Called to "clear" patient for Right hip fracture. Pt denies cp, cardiac enzymes are negative. He is noted to be in A. fib with a rate of 115. *
Patient is to proceed with surgery without further intervention.
Patient's (revised cardiac risk index) places him at a 6.6% chance of perioperative cardaic event.
Patient should have a stress test prior to surgery.
Answer: Surgery needs to be delayed due to the active cardiac problem of A. fib with RVR until pt's HR is under 100.
Discussion: This may have surprised a few people! This is a common situation. Hip fracture is a relative emergent surgery, requiring intervention with preference of within 48 hours. With this knowledge, active cardiac issues need to be cared for (step two of algorithm). What are the “active cardiac issues”? These are issues that would get the patient admitted into the hospital all by themselves.
Many things on the list are pretty obvious. The one surprise is the recommendation for Atrial Fibrillation: HR needs to be under 100 at rest. For this reason, the surgery should be delayed and patient’s heart heart controlled. If the surgery is emergent as in needing surgery now, then the answer would be to proceed to the OR.
Patients revised cardiac risk index is 3 placing him at a 11% risk of perioperative cardiac event. Stress testing would not change the management. Many things on the list are pretty obvious. The one surprise is the recommendation for Atrial Fibrillation: HR needs to be under 100 at rest. For this reason, the surgery should be delayed and patient’s heart heart controlled. If the surgery is emergent as in needing surgery now, then the answer would be to proceed to the OR.
Patients RCRI is 3 placing him at a 11% risk of perioperative cardiac event. Stress testing would not change the management. 4. 56 y/o PMH significant for CAD with recent stent placed in LAD 2 months ago. Pt presents for 'clearance' for planned cholecystectomy. *
Answer: If the patient had a bare metal stent, proceed with surgery.
Patient should stop his aspirin prior to surgery.
Patient should stop his metoprolol prior to surgery due to risk of CVA.
If patient had a drug eluting stent, surgery should be delayed for 6 months.
Discussion: Following placement of a bare metal stent, it is recommended patients wait 45 days prior to any elective procedure. This covers the time frame the patient needs to be on plavix and aspirin combination. The patient should still continue asa though, and if the surgery is unwilling to operate with asa, then the surgery should be delayed.
Stopping beta blockers during the perioperative period is associated with increased cardiac events. With this in mind, patients who are on beta blockers and need to be NPO following a surgery need to be placed on IV metoprolol with strict instructions. The up and down of the heart rate is believed to be the etiology for the increased cardiac events. Metoprolol started acutely prior to surgery is associated with increased cardiac events.
Surgery should be delayed for 12 months following the placement of a drug eluting stent.
5. 56 y/o male with PMH DM, CHF (EF 40%), HTN, CAD who presented for preoperative evaluation for a cholecystectomy. Patient is without any complaints. He is able to go up two flights of stairs without stopping. *
Answer: Patient can proceed with surgery without any further intervention.
Patient's revised cardiac risk index is 2.
Patient cannot achieve an estimated 4 METS.
Patient should have a stress test prior to surgery.
Discussion: Functional capacity is extremely important but often under appreciated in medicine. This patient can achieve an estimated 4 Estimating METS demonstrating that the patient has excellent functional capacity. Despite having a high revised cardiac risk index (3: 11% risk of perioperative cardiac event for all comers), he does not require any intervention and may proceed to the OR due to having a much lower risk based upon be able to achieve 4 METS (Estimated Tolerance and Serious Perioperative Cardiac Events).
Utilizing the algorithm:
1. Not an emergent surgery.
2. No active cardiac conditions
3. Not a low risk procedure.
4. Patient is able to achieve 4 METS.
One question that may still be out there is when should someone get a stress test? That is a great question! Reviewing the algorithm, once you get to the very bottom, it will state to consider a stress test if it will change the management. So, when will it change the management? We need to first consider what our options are: Cath, CABG, Beta-blocker, Statin, and cancel surgery (surgery considered just too high of risk). So, which of the above actually changes the outcome?
- Cath: It would seem to make sense that a preoperative cath would reduce events. The data does not support this! Preoperative caths do not reduce cardiac events. Caths should be performed purely for cardiac indications, not for a surgery. If the patient meets indications for the cath and stent based upon cardiac problems, then that needs to be addressed. Otherwise, it is not helpful.
- What about CABG? This has actually been helpful. Now, thinking about it, this should not be a surprise. There maybe some selection bias on this. If a patient survives a CABG, he is likely to survive a cholecystectomy. The patients that would likely have a complication from a cholecystectomy, is not going to survive their CABG! So, again, a CABG is only indicated if they meet cardiac indications for a CABG. Don’t do it just for a surgery.
- Beta-blocker: As reviewed above, this has been shown to be beneficial, although there maybe some risks, especially if started acutely. Some have advocated to perform stress test for pts with a revised cardiac risk index of 2, and if there is some evidence for ischemia, then use the beta blocker for them. Based upon the algorithms, if the patient is unable to complete 4 METS and has a RCRI of 1 or more, then they should be placed on a beta-blocker for at least 7 days (I prefer 14) prior to surgery.
- Statin: Statins have evidence of benefit for patients going to vascular surgery, but it is suspected it is beneficial for all surgeries. Because there is a lack of evidence at this time, the recommendation is to consider a statin for those patient who can not achieve 4 METS and have a RCRI of 1 or higher.
- Cancel Surgery: So, who should get a stress then? If nothing can be done about a bad stress test, why stress anyone? I stress if it will help the patient or surgeon understand better the risk so that the patient can truly make an informed consent. Meaning, if the patient or surgeon would cancel the surgery because the patient is so high risk (or they are on the border whether they want to do it), then I stress the patient. If there isn't a question on whether to proceed to surgery, then I do not stress.
Patient should be started on metoprolol and proceed to the OR.
Answer: Patient should proceed with surgery.
Patient should have a stress test prior to surgery.
Surgery should be delayed x 1 year.
Discussion: This patient presents with a surgical emergency, requiring emergent surgery. Metoprolol would prevent perioperative cardiac events, if on a stable dose for 2 weeks prior to surgery (POISE). Please note though, that acute withdraw of metoprolol is also associated with INCREASED perioperative cardiac events, so this pt must be continued on metoprolol if already on it (change to IV).
Stress testing would not change the management, and is not indicated. If this was an elected surgery, then it would need to be delayed x 1 year as stated above. It would be strongly recommended that this pt continue his plavix during the perioperative time due to the high risk of instent thrombosis.