Heart Bypass Operation

Heart Bypass Operation (Coronary Artery Bypass Graft or CABG) is a surgical procedure that restores blood flow around a blocked artery of the heart. The blockage is usually the result of a build-up of fats in and on the artery walls. The procedure uses a blood vessel from the chest, leg, or arm. This vessel is connected to the artery, bypassing the diseased or blocked area, thus restoring blood flow to the heart.

In evaluating our performance, it is important to consider several types of measures, including adherence to best practices (or care process) and the success (or outcome) of the procedure. The Society of Thoracic Surgeons (STS) provides national benchmarks for this procedure to help hospitals evaluate their performance.

As you review the graphs below, you will see that the University of Michigan Health System usually exceeds the STS national benchmarks.

Procedure volume is the number of times a procedure was performed. The measure is often used to assess clinical experience and expertise. Studies have linked higher volumes with more successful outcomes for some types of procedures. The following graphs display the total number of heart bypass operations and the number of "isolated" heart bypass operations.

Total Number of Heart Bypass Operations

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Why is This Measure Important?

This is a measure of the volume, or number of CABG operations that are performed either as the only operation or as operations performed the same time as a heart valve or other heart procedure. It is important to consider both volume and outcome measures when assessing quality of care.

How is UMHS Performing?

Surgeons at the University of Michigan Health System performed a substantial number of CABG procedures in the past six years. At UMHS, cardiac surgeons and cardiologists collaborate to determine the best treatment for each patient - CABG, angioplasty and stent, or medi. Today, patients who receive a CABG procedure are likely to have more complex conditions.

UMHS Source: University of Michigan Cardiac Surgery Clinical Database.

Number of Isolated Heart Bypass Operations

Details

Why is This Measure Important?

This is a measure of the volume, or number of “isolated” CABG operations. The measure does not include CABG operations that are performed at the same time as heart valve or other heart procedure. It is important to consider both volume and outcome measures when assessing quality of care.

How is UMHS Performing?

Surgeons at the University of Michigan Health System performed a substantial but decreasing number of isolated CABG procedures in the past six years. The volume is decreasing because more patients are being treated with less invasive procedures like angioplasty and stents. At UMHS, cardiac surgeons and cardiologists collaborate to determine the best treatment for each patient - CABG or angioplasty and stent. Today, patients who receive a CABG procedure are likely to have more complex conditions.

UMHS Source: University of Michigan Cardiac Surgery Clinical Database.

The following graphs describe the performance of the University of Michigan Health System by measuring the extent to which we follow best practices when performing CABG surgery. These best practices are also called evidence-based processes of care. When followed, they may lead to better outcomes.

Anti-platelet Medication Prescribed at Discharge
Higher Value = Better Performance

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Why is This Measure Important?

Antiplatelet medications prevent a component of blood called platelets from forming a blood clot within your body. These medications can prevent a post-operative blood clot from forming in the healthy blood vessel that was used to bypass the blocked artery in the heart.

How is UMHS Performing?

The University of Michigan Health System's performance in this measure is high and slightly higher than the Society of Thoracic Surgeons (STS) national average.

UMHS Source: Hospital administrative data and chart review.
Comparison Group Source: National performance from Society of Thoracic Surgeons.

Beta Blocker Medications Prior to Operation
Higher Value = Better Performance

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Why is This Measure Important?

Beta Blockers are medications that are used to control the rate at which the heart beats. Administration of beta blockers at the time of operation may decrease post-surgery atrial fibrillation (a fast, irregular heart rate) and, when indicated, can help protect the heart from further damage.

How is UMHS Performing?

The University of Michigan Health System is slightly below the Society of Thoracic Surgeons (STS) national average in administering beta blocker medications at the time of operation. We are continuously working to improve our performance in this measure.

UMHS Source: Hospital administrative data and chart review.
Comparison Group Source: National performance from Society of Thoracic Surgeons.

Cholesterol Medications Prescribed at Discharge
Higher Value = Better Performance

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Why is This Measure Important?

Cholesterol-lowering medication should be prescribed for patients who undergo a CABG procedure before they leave the hospital. This medication helps reduce deposits of fatty material into arteries of the heart, which can lead to new blockages, and may also reduce inflamation.

How is UMHS Performing?

The University of Michigan Health System has performed exceptionally well in this best practice. Our performance in prescribing cholesterol-lowering medication is better than the Society of Thoracic Surgeons (STS) national average.

UMHS Source: Hospital administrative data and chart review.
Comparison Group Source: National performance from Society of Thoracic Surgeons.

Beta Blocker Medications Prescribed at Discharge
Higher Value = Better Performance

Details

Why is This Measure Important?

Beta blocker medication should be prescribed for patients who undergo a CABG procedure before they leave the hospital. This medication helps lower blood pressure and heart rate.

How is UMHS Performing?

The University of Michigan Health System has performed well in this best practice. Our performance in prescribing beta blocker medication is slightly lower than the Society of Thoracic Surgeons (STS) national average.

UMHS Source: Hospital administrative data and chart review.
Comparison Group Source: National performance from Society of Thoracic Surgeons.

Internal Mammary Artery Use in Bypass Procedures
Higher Value = Better Performance

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Why is This Measure Important?

Internal Mammary arteries are used in most coronary artery bypass. These arteries are proven to stay open (patent) longer than veins used from the leg.

How is UMHS Performing?

The University of Michigan Health System has achieved a rate of 100% during the last 4 out of 5 measurement periods.

UMHS Source: Hospital administrative data and chart review.
Comparison Group Source: National performance from Society of Thoracic Surgeons.

In this section, we evaluate the success of the isolated CABG procedures by measuring the occurrence of complications within 30 days after the procedure was performed. We compare our rates to the national average, provided by the Society of Thoracic Surgeons (STS). The risk of developing complications depends on many factors, including the patient's health condition prior to undergoing the procedure. The risk of the patients we treat may be greater than the risk of patients represented in the STS average, because the University of Michigan Health System treats many complex patients who have heart disease and other serious medical problems. However, as the graphs below show, UMHS is very successful in managing these complex cases.

In all of these graphs, a lower percentage means fewer complications and better performance. The graphs show that most patients who underwent an isolated CABG procedure at UMHS rarely experience complications and our complication and death rates are often lower than the STS national average.

Wound Infections w/in 30 Days of Operation
Higher Value = Better Performance

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Why is This Measure Important?

Wound infections following CABG procedures that involve the breastbone or that are deep within the chest are serious infections. Patients with diabetes or who are obese have a greater risk of developing a wound infection. For this and all other outcome measures, lower percentages are better.

How is UMHS Performing?

The University of Michigan Health System's performance was higher than the national average reported by the Society of Thoracic Surgeons (STS). Each occurrence of an infection is reviewed and analysis is completed to identify opportunities for improvement. We continually strive to reduce the occurrence of infections.

UMHS Source: University of Michigan Cardiac Surgery Clinical Database.
Comparison Group Source: National performance from Society of Thoracic Surgeons.

Kidney Problems w/in 30 Days of Operation
Higher Value = Better Performance

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Why is This Measure Important?

Kidney problems are another complication for patients undergoing a CABG procedure. Patients with a history of kidney disease have a greater risk of kidney problems after CABG. Most patients recover their kidney function in the weeks following surgery. For this and all other outcome measures, lower percentages are better.

How is UMHS Performing?

The University of Michigan Health System's performance is worse than the national average reported by the Society of Thoracic Surgeons (STS). We continue the collaboration between cardiac surgeons and cardiologists to establish hydration protocols and schedule CABG operations when kidney problems are less likely occur.

UMHS Source: University of Michigan Cardiac Surgery Clinical Database.
Comparison Group Source: National performance from Society of Thoracic Surgeons.

Stroke within 30 Days of Operation
Higher Value = Better Performance

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Why is This Measure Important?

Stroke is a possible complication for patients undergoing a CABG procedure. Older patients and patients with previous history of stroke have a greater risk of stroke after CABG. For this and all other outcome measures, lower percentages are better.

How is UMHS Performing?

The University of Michigan Health System's performance is better than the national average reported by the Society of Thoracic Surgeons (STS). Our rate continues to be lower than the STS national average.

UMHS Source: University of Michigan Cardiac Surgery Clinical Database.
Comparison Group Source: National performance from Society of Thoracic Surgeons.

Deaths within 30 Days of Operation
Higher Value = Better Performance

Details

Why is This Measure Important?

The mortality rate is the percentage of patients who die after undergoing a CABG procedure. This is a measure of mortality rate within 30 days after CABG. For this and all other outcome measures, lower percentages are better.

How is UMHS Performing?

The University of Michigan Health System treats many complex patients who have heart disease and other serious medical problems and is successful in managing these complex clinical cases. The University of Michigan Health System's performance is substantially better than the national average reported by the Society of Thoracic Surgeons (STS) in all five years.

UMHS Source: University of Michigan Cardiac Surgery Clinical Database.
Comparison Group Source: National performance from Society of Thoracic Surgeons.