Delaying Surgery After PCI Cuts Kidney Injury

FORT LAUDERDALE, FLA. — Combining coronary artery catheterization and cardiac surgery in the same hospital admission was linked to a significantly increased risk for acute kidney injury, compared with performing the surgery during a second, later hospitalization, a single-center study of more than 600 patients showed.

Acute kidney injury (AKI) in cardiac surgery patients represents an important complication. Results from an earlier study linked it to significantly worse long-term survival, Dr. Robert S. Kramer said at the annual meeting of the Society of Thoracic Surgeons.

“If there is a way to safely manage patients medically between catheterization and surgery, that should be done, to mitigate the potential for acute kidney injury,” said Dr. Kramer, director of cardiac surgery research at Maine Medical Center in Portland. He acknowledged that some patients have urgent medical reasons to undergo cardiac surgery within days of their percutaneous coronary intervention (PCI), such as patients with an acute MI, life-threatening coronary anatomy, or another acute syndrome that mandates quick surgery. However, in many other cases, cardiac surgery becomes scheduled during the same hospital admission as PCI because of convenience for the patient, the surgeon, or other physicians involved with the case.

“We want cardiac surgeons to look at the whole picture and consider whether it would be better for the patient to go home and settle down if there is no reason to act right now,” he said in an interview. “We hypothesize that there may be an opportunity to reduce the incidence of acute kidney injury by moving patients who may be safely changed from the urgent to nonurgent category.”

The study reviewed 722 consecutive patients who underwent cardiac surgery subsequent to PCI at Maine Medical Center during 2008. The analysis excluded 41 patients who required emergency procedures while hospitalized, 5 who were on dialysis, and 8 who did not have cardiac catheterization in the days or weeks before their surgery, leaving 668 patients in the study. Surgery occurred during a subsequent hospitalization following catheterization in 211 patients, while in 457, surgery followed catheterization during the same hospitalization. Among patients with delayed surgery, the period between catheterization and surgery averaged 39 days. In patients who had both procedures in one admission, the delay between catheterization and surgery averaged 3 days.

The patients' average age was 68 years, and about a quarter were women. Patients with immediate surgery and those with delayed surgery were similar in the prevalence of most comorbidities and clinical characteristics. The immediate surgery patients had a significantly higher prevalence of coronary artery disease, 83% compared with 75%; a higher prevalence of MI during the week preceding surgery, 25% compared with 1%; a higher prevalence of a left ventricular ejection fraction of less than 40%, 14% compared with 8%; and a higher prevalence of an elevated white cell count.

The rates of elective and urgent surgery, respectively, were 86% and 14% in the patients whose surgery was deferred for a second hospitalization, compared with 13% and 87% in patients who had their catheterization and surgery in a single hospitalization. Coronary bypass surgery alone occurred in 53% of the deferred patients and 60% of those with a single hospitalization, with the other surgeries divided between valve alone or valve plus bypass.

The incidence of AKI during or immediately after surgery was 34% in the patients who came back to the hospital a second time for their surgery and 50% in those who had their surgery soon after their catheterization, a statistically significant difference. Dr. Kramer and his associates used an AKI definition devised by the AKI Network: a creatinine measure that increased by at least 50% over baseline or that rose by at least 0.3 mg/dL over baseline. All patients in the review had their serum creatinine levels measured at baseline and several times during and after surgery.

No other perioperative outcome parameters differed significantly between the two groups, including death, Q-wave MI, or stroke. The perioperative mortality rate was 2% in patients with deferred surgery and 4% in those with more immediate surgery.

In an analysis that adjusted for baseline demographic and clinical differences, patients with deferred surgery had a significant, 45% relative reduction in their rate of AKI, compared with patients with more immediate surgery.

Dr. Kramer and his associates documented the potential importance of AKI in a study they reported at the American Heart Association scientific sessions last November in Orlando. During 5-year follow-up of about 4,000 cardiac surgery patients, the survival rate was about 95% in patients who did not have any AKI perioperatively, compared with about 80% in those who experienced AKI.

“Creatinine levels and AKI are surrogates for bad epiphenomenon” in patients following cardiac surgery. “The kidney is the canary in the mine shaft,” Dr. Kramer said.

It's unclear what it is about scheduling cardiac surgery several days or weeks following coronary catheterization that cuts the risk of AKI. Contrast administered during coronary catheterization “is a major player, but other factors also play a role. It's not that the contrast clears, but contrast causes tubular injury that has to heal and does heal within a few days.” Based on other studies, he speculated that a delay of at least 5 days is ideal.

He cautioned that the finding was limited by the retrospective, single-center nature of the study. But it involved a relatively large number of patients, and creatinine level checks occurred prospectively and uniformly for all patients, eliminating potential ascertainment bias.

Although the findings are just hypothesis generating, Dr. Kramer contended that the findings are compelling enough to warrant an immediate change in practice: Limit cardiac surgery within a few days after catheterization to patients who clearly need rapid intervention.

Disclosures: Dr. Kramer said he had no disclosures relevant to this study.

A related video is at www.youtube.com/HospitalistNews

FORT LAUDERDALE, FLA. — Combining coronary artery catheterization and cardiac surgery in the same hospital admission was linked to a significantly increased risk for acute kidney injury, compared with performing the surgery during a second, later hospitalization, a single-center study of more than 600 patients showed.

Acute kidney injury (AKI) in cardiac surgery patients represents an important complication. Results from an earlier study linked it to significantly worse long-term survival, Dr. Robert S. Kramer said at the annual meeting of the Society of Thoracic Surgeons.

“If there is a way to safely manage patients medically between catheterization and surgery, that should be done, to mitigate the potential for acute kidney injury,” said Dr. Kramer, director of cardiac surgery research at Maine Medical Center in Portland. He acknowledged that some patients have urgent medical reasons to undergo cardiac surgery within days of their percutaneous coronary intervention (PCI), such as patients with an acute MI, life-threatening coronary anatomy, or another acute syndrome that mandates quick surgery. However, in many other cases, cardiac surgery becomes scheduled during the same hospital admission as PCI because of convenience for the patient, the surgeon, or other physicians involved with the case.

“We want cardiac surgeons to look at the whole picture and consider whether it would be better for the patient to go home and settle down if there is no reason to act right now,” he said in an interview. “We hypothesize that there may be an opportunity to reduce the incidence of acute kidney injury by moving patients who may be safely changed from the urgent to nonurgent category.”

The study reviewed 722 consecutive patients who underwent cardiac surgery subsequent to PCI at Maine Medical Center during 2008. The analysis excluded 41 patients who required emergency procedures while hospitalized, 5 who were on dialysis, and 8 who did not have cardiac catheterization in the days or weeks before their surgery, leaving 668 patients in the study. Surgery occurred during a subsequent hospitalization following catheterization in 211 patients, while in 457, surgery followed catheterization during the same hospitalization. Among patients with delayed surgery, the period between catheterization and surgery averaged 39 days. In patients who had both procedures in one admission, the delay between catheterization and surgery averaged 3 days.

The patients' average age was 68 years, and about a quarter were women. Patients with immediate surgery and those with delayed surgery were similar in the prevalence of most comorbidities and clinical characteristics. The immediate surgery patients had a significantly higher prevalence of coronary artery disease, 83% compared with 75%; a higher prevalence of MI during the week preceding surgery, 25% compared with 1%; a higher prevalence of a left ventricular ejection fraction of less than 40%, 14% compared with 8%; and a higher prevalence of an elevated white cell count.

The rates of elective and urgent surgery, respectively, were 86% and 14% in the patients whose surgery was deferred for a second hospitalization, compared with 13% and 87% in patients who had their catheterization and surgery in a single hospitalization. Coronary bypass surgery alone occurred in 53% of the deferred patients and 60% of those with a single hospitalization, with the other surgeries divided between valve alone or valve plus bypass.

The incidence of AKI during or immediately after surgery was 34% in the patients who came back to the hospital a second time for their surgery and 50% in those who had their surgery soon after their catheterization, a statistically significant difference. Dr. Kramer and his associates used an AKI definition devised by the AKI Network: a creatinine measure that increased by at least 50% over baseline or that rose by at least 0.3 mg/dL over baseline. All patients in the review had their serum creatinine levels measured at baseline and several times during and after surgery.

No other perioperative outcome parameters differed significantly between the two groups, including death, Q-wave MI, or stroke. The perioperative mortality rate was 2% in patients with deferred surgery and 4% in those with more immediate surgery.

In an analysis that adjusted for baseline demographic and clinical differences, patients with deferred surgery had a significant, 45% relative reduction in their rate of AKI, compared with patients with more immediate surgery.

Dr. Kramer and his associates documented the potential importance of AKI in a study they reported at the American Heart Association scientific sessions last November in Orlando. During 5-year follow-up of about 4,000 cardiac surgery patients, the survival rate was about 95% in patients who did not have any AKI perioperatively, compared with about 80% in those who experienced AKI.

“Creatinine levels and AKI are surrogates for bad epiphenomenon” in patients following cardiac surgery. “The kidney is the canary in the mine shaft,” Dr. Kramer said.

It's unclear what it is about scheduling cardiac surgery several days or weeks following coronary catheterization that cuts the risk of AKI. Contrast administered during coronary catheterization “is a major player, but other factors also play a role. It's not that the contrast clears, but contrast causes tubular injury that has to heal and does heal within a few days.” Based on other studies, he speculated that a delay of at least 5 days is ideal.

He cautioned that the finding was limited by the retrospective, single-center nature of the study. But it involved a relatively large number of patients, and creatinine level checks occurred prospectively and uniformly for all patients, eliminating potential ascertainment bias.

Although the findings are just hypothesis generating, Dr. Kramer contended that the findings are compelling enough to warrant an immediate change in practice: Limit cardiac surgery within a few days after catheterization to patients who clearly need rapid intervention.

Disclosures: Dr. Kramer said he had no disclosures relevant to this study.

A related video is at www.youtube.com/HospitalistNews

FORT LAUDERDALE, FLA. — Combining coronary artery catheterization and cardiac surgery in the same hospital admission was linked to a significantly increased risk for acute kidney injury, compared with performing the surgery during a second, later hospitalization, a single-center study of more than 600 patients showed.

Acute kidney injury (AKI) in cardiac surgery patients represents an important complication. Results from an earlier study linked it to significantly worse long-term survival, Dr. Robert S. Kramer said at the annual meeting of the Society of Thoracic Surgeons.

“If there is a way to safely manage patients medically between catheterization and surgery, that should be done, to mitigate the potential for acute kidney injury,” said Dr. Kramer, director of cardiac surgery research at Maine Medical Center in Portland. He acknowledged that some patients have urgent medical reasons to undergo cardiac surgery within days of their percutaneous coronary intervention (PCI), such as patients with an acute MI, life-threatening coronary anatomy, or another acute syndrome that mandates quick surgery. However, in many other cases, cardiac surgery becomes scheduled during the same hospital admission as PCI because of convenience for the patient, the surgeon, or other physicians involved with the case.

“We want cardiac surgeons to look at the whole picture and consider whether it would be better for the patient to go home and settle down if there is no reason to act right now,” he said in an interview. “We hypothesize that there may be an opportunity to reduce the incidence of acute kidney injury by moving patients who may be safely changed from the urgent to nonurgent category.”

The study reviewed 722 consecutive patients who underwent cardiac surgery subsequent to PCI at Maine Medical Center during 2008. The analysis excluded 41 patients who required emergency procedures while hospitalized, 5 who were on dialysis, and 8 who did not have cardiac catheterization in the days or weeks before their surgery, leaving 668 patients in the study. Surgery occurred during a subsequent hospitalization following catheterization in 211 patients, while in 457, surgery followed catheterization during the same hospitalization. Among patients with delayed surgery, the period between catheterization and surgery averaged 39 days. In patients who had both procedures in one admission, the delay between catheterization and surgery averaged 3 days.

The patients' average age was 68 years, and about a quarter were women. Patients with immediate surgery and those with delayed surgery were similar in the prevalence of most comorbidities and clinical characteristics. The immediate surgery patients had a significantly higher prevalence of coronary artery disease, 83% compared with 75%; a higher prevalence of MI during the week preceding surgery, 25% compared with 1%; a higher prevalence of a left ventricular ejection fraction of less than 40%, 14% compared with 8%; and a higher prevalence of an elevated white cell count.

The rates of elective and urgent surgery, respectively, were 86% and 14% in the patients whose surgery was deferred for a second hospitalization, compared with 13% and 87% in patients who had their catheterization and surgery in a single hospitalization. Coronary bypass surgery alone occurred in 53% of the deferred patients and 60% of those with a single hospitalization, with the other surgeries divided between valve alone or valve plus bypass.

The incidence of AKI during or immediately after surgery was 34% in the patients who came back to the hospital a second time for their surgery and 50% in those who had their surgery soon after their catheterization, a statistically significant difference. Dr. Kramer and his associates used an AKI definition devised by the AKI Network: a creatinine measure that increased by at least 50% over baseline or that rose by at least 0.3 mg/dL over baseline. All patients in the review had their serum creatinine levels measured at baseline and several times during and after surgery.

No other perioperative outcome parameters differed significantly between the two groups, including death, Q-wave MI, or stroke. The perioperative mortality rate was 2% in patients with deferred surgery and 4% in those with more immediate surgery.

In an analysis that adjusted for baseline demographic and clinical differences, patients with deferred surgery had a significant, 45% relative reduction in their rate of AKI, compared with patients with more immediate surgery.

Dr. Kramer and his associates documented the potential importance of AKI in a study they reported at the American Heart Association scientific sessions last November in Orlando. During 5-year follow-up of about 4,000 cardiac surgery patients, the survival rate was about 95% in patients who did not have any AKI perioperatively, compared with about 80% in those who experienced AKI.

“Creatinine levels and AKI are surrogates for bad epiphenomenon” in patients following cardiac surgery. “The kidney is the canary in the mine shaft,” Dr. Kramer said.

It's unclear what it is about scheduling cardiac surgery several days or weeks following coronary catheterization that cuts the risk of AKI. Contrast administered during coronary catheterization “is a major player, but other factors also play a role. It's not that the contrast clears, but contrast causes tubular injury that has to heal and does heal within a few days.” Based on other studies, he speculated that a delay of at least 5 days is ideal.

He cautioned that the finding was limited by the retrospective, single-center nature of the study. But it involved a relatively large number of patients, and creatinine level checks occurred prospectively and uniformly for all patients, eliminating potential ascertainment bias.

Although the findings are just hypothesis generating, Dr. Kramer contended that the findings are compelling enough to warrant an immediate change in practice: Limit cardiac surgery within a few days after catheterization to patients who clearly need rapid intervention.

Disclosures: Dr. Kramer said he had no disclosures relevant to this study.

A related video is at www.youtube.com/HospitalistNews