Paul D McGrath

Survival of patients with diabetes and multivessel coronary artery disease after surgical or percutaneous coronary revascularization: results of a large regional prospective study

OBJECTIVES We sought to assess survival among patients with diabetes and multivessel coronary artery disease (MVD) after percutaneous coronary intervention (PCI) and after coronary artery bypass grafting surgery (CABG). BACKGROUND The Bypass Angioplasty Revascularization Investigation (BARI) demonstrated that diabetics with MVD survive longer after initial CABG than after initial PCI. Other randomized trials or observational databases have not conclusively reproduced this result. METHODS A large, regional database was linked to the National Death Index to assess five-year mortality. Of 7,159 consecutive patients with diabetes who underwent coronary revascularization in northern New England during 1992 to 1996, 2,766 (38.6%) were similar to those randomized in the BARI trial. Percutaneous coronary intervention was the initial revascularization strategy in 736 patients and CABG in 2,030. Cox proportional hazards regression was used to calculate risk-adjusted hazard ratios (HR) and 95% confidence intervals (CI 95%). RESULTS Patients who underwent PCI were younger, had higher ejection fractions and less extensive coronary disease. After adjusting for differences in baseline clinical characteristics, patients with diabetes treated with PCI had significantly greater mortality relative to those undergoing CABG (HR = 1.49; CI 95%: 1.02 to 2.17; p = 0.037). Mortality risk tended to increase more among 1,251 patients with 3VD (HR = 2.02; CI 95%: 1.04 to 3.91; p = 0.038) than among 1,515 patients with 2VD (HR = 1.33; CI 95%: 0.84 to 2.1; p = 0.21). CONCLUSIONS In this analysis of a large regional contemporary database of patients with diabetes selected to be similar to those enrolled in the BARI trial, five-year mortality was significantly increased after initial PCI. This supports the BARI conclusion on initial revascularization of patients with diabetes and MVD.

Predicting vascular complications in percutaneous coronary interventions

OBJECTIVES Using a large, current, regional registry of percutaneous coronary interventions (PCI), we identified risk factors for postprocedure vascular complications and developed a scoring system to estimate individual patient risk. BACKGROUND A vascular complication (access-site injury requiring treatment or bleeding requiring transfusion) is a potentially avoidable outcome of PCI. METHODS Data were collected on 18,137 consecutive patients undergoing PCI in northern New England from January 1997 to December 1999. Multivariate regression was used to identify characteristics associated with vascular complications and to develop a scoring system to predict risk. RESULTS The rate of vascular complication was 2.98% (541 cases). Variables associated with increased risk in the multivariate analysis included age >or=70, odds ratio (OR) 2.7, female sex (OR 2.4), body surface area <1.6 m(2) (OR 1.9), history of congestive heart failure (OR 1.4), chronic obstructive pulmonary disease (OR 1.5), renal failure (OR 1.9), lower extremity vascular disease (OR 1.4), bleeding disorder (OR 1.68), emergent priority (OR 2.3), myocardial infarction (OR 1.7), shock (1.86), >or=1 type B2 (OR 1.32) or type C (OR 1.7) lesions, 3-vessel PCI (OR 1.5), use of thienopyridines (OR 1.4) or use of glycoprotein IIb/IIIa receptor inhibitors (OR 1.9). The model performed well in tests for significance, discrimination, and calibration. The scoring system captured 75% of actual vascular complications in its highest quintiles of predicted risk. CONCLUSION Predicting the risk of post-PCI vascular complications is feasible. This information may be useful for clinical decision-making and institutional efforts at quality improvement.

Mediastinitis and long-term survival after coronary artery bypass graft surgery

BACKGROUND Mediastinitis is a dreaded complication of coronary artery bypass surgery (CABG). The long-term effect of mediastinitis on mortality after CABG has not been well studied. METHODS We examined the survival of 15,406 consecutive patients undergoing isolated CABG surgery from 1992 through 1996. Patient records were linked to the National Death Index. Mediastinitis was defined as occurring during the index admission and requiring reoperation. RESULTS Mediastinitis occurred in 193 patients (1.25%). Patients with mediastinitis were older and more likely to have had emergency surgery, diabetes, peripheral vascular disease, chronic obstructive pulmonary disease, and preoperative dialysis-dependent renal failure. Patients with mediastinitis were also more likely to be severely obese and had somewhat lower preoperative ejection fraction. After multivariate adjustment for these factors, the first year post-CABG survival rate was 78% with mediastinitis and 95% without, and the hazard ratio for mortality during the entire follow-up period was 3.09 (CI 95% 2.28, 4.19; p < 0.0001). CONCLUSIONS Mediastinitis is associated with a marked increase in mortality during the first year post-CABG and a threefold increase during a 4-year follow-up period.

Multivariate prediction of in-hospital mortality after percutaneous coronary interventions in 1994-1996

OBJECTIVES Using recent data, we sought to identify risk factors associated with in-hospital mortality among patients undergoing percutaneous coronary interventions. BACKGROUND The ability to accurately predict the risk of an adverse outcome is important in clinical decision making and for risk adjustment when assessing quality of care. Most clinical prediction rules for percutaneous coronary intervention (PCI) were developed using data collected before the broader use of new interventional devices. METHODS Data were collected on 15,331 consecutive hospital admissions by six clinical centers. Logistic regression analysis was used to predict the risk of in-hospital mortality. RESULTS Variables associated with an increased risk of in-hospital mortality included older age, congestive heart failure, peripheral or cerebrovascular disease, increased creatinine levels, lowered ejection fraction, treatment of cardiogenic shock, treatment of an acute myocardial infarction, urgent priority, emergent priority, preprocedure insertion of an intraaortic balloon pump and PCI of a type C lesion. The receiver operating characteristic area for the predicted probability of death was 0.88, indicating a good ability to discriminate. The rule was well calibrated, predicting accurately at all levels of risk. Bootstrapping demonstrated that the estimate was stable and performed well among different patient subsets. CONCLUSIONS In the current era of interventional cardiology, accurate calculation of the risk of in-hospital mortality after a percutaneous coronary intervention is feasible and may be useful for patient counseling and for quality improvement purposes.

Gender-related changes in the practice and outcomes of percutaneous coronary interventions in Northern New England from 1994 to 1999.

OBJECTIVES We sought to determine whether the changing practice of interventional cardiology has been associated with improved outcomes for women, and how these outcomes compare with those for men. BACKGROUND Previous work from the early 1990s suggested women are at a higher risk than men for adverse outcomes after percutaneous coronary interventions (PCIs). From 1994 to 1999 data were collected on 33,666 consecutive hospital admissions for a PCI in Northern New England. Multivariate models were used to adjust for differences in case-mix across year of procedure when comparing outcomes. Direct standardization was used to calculate adjusted rates. RESULTS From 1994 to 1999, the case-mix worsened for both women and men, although women had more co-morbidities than did men throughout the period. Stent use increased over time (>75% in 1999). Concomitantly, the need for emergency coronary artery bypass graft surgery (CABG) decreased significantly (p(trend) < or = 0.001; in 1999: 0.06% for women, 0.05% for men). Although the emergency CABG rates were higher for women at the beginning of the study, by the end, they were comparable (adjusted odds ratio 1.34, 95% confidence interval 0.76 to 2.38, p = 0.315). The myocardial infarction (MI) rates decreased over time for both women (by 29.7%, p(trend) = 0.378) and men (by 37.6%, p(trend) = 0.009) and did not differ by gender. The mortality rates did not decrease significantly over time and were not significantly different between the genders (mean 1.21% for women, 1.06% for men; p = 0.096). CONCLUSIONS Concurrent with the changing practice of PCI, and despite treating sicker patients, there have been important improvements in post-PCI CABG and MI rates for women, as well as for men. Unlike in earlier years, there are no longer significant differences in outcomes by gender.

The relationship between operator volume and outcomes after percutaneous coronary interventions in high volume hospitals in 1994–1996: The northern New England experience

OBJECTIVES The purpose of this study was to examine the relationship between annual operator volume and outcomes of percutaneous coronary interventions (PCIs) using contemporaneous data. BACKGROUND The 1997 American College of Cardiology (ACC)/American Heart Association task force based their recommendation that interventionists perform > or = 75 procedures per year to maintain competency in PCI on data collected largely in the early 1990s. The practice of interventional cardiology has since changed with the availability of new devices and drugs. METHODS Data were collected from 1994 through 1996 on 15,080 PCIs performed during 14,498 hospitalizations by 47 interventional cardiologists practicing at the five high volume (>600 procedures per hospital per year) hospitals in northern New England and one Massachusetts-based institution that support these procedures. Operators were categorized into terciles based on their annualized volume of procedures. Multivariate regression analysis was used to control for case-mix. In-hospital outcomes included death, emergency coronary artery bypass graft surgery (eCABG), non-emergency CABG (non-eCABG), myocardial infarction (MI), death and clinical success (> or = 1 attempted lesion dilated to < 50% residual stenosis and no death, CABG or MI). RESULTS Average annual procedure rates varied across terciles from low = 68, middle = 115 and high = 209. After adjusting for case-mix, clinical success rates were comparable across terciles (low, middle and high terciles: 90.9%, 88.8% and 90.7%, Ptrend = 0.237), as were all the adverse outcomes including death (low-risk patients = 0.45%, 0.41%, 0.71%, Ptrend = 0.086; high-risk patients = 5.68%, 5.99%, 7.23%, Ptrend = 0.324), eCABG (1.74%, 2.05%, 1.75%, Ptrend = 0.733) and MI (2.57%, 1.90%, 1.86%, Ptrend = 0.065). CONCLUSIONS Using current data, there is no significant relationship between operator volumes averaging > or = 68 per year and outcomes at high volume hospitals. Future efforts should be directed at determining the generalizability of these results.

Operator Volume and Outcomes in 12,988 Percutaneous Coronary Interventions

OBJECTIVES We sought to determine whether there is a relation between operator volume and outcomes for percutaneous coronary interventions (PCIs). BACKGROUND A 1993 American College of Cardiology/American Heart Association task force stated that cardiologists should perform > or = 75 procedures/year to maintain competency in PCIs; however, there were limited data available to support this statement. METHODS Data were collected from 1990 through 1993 on 12,988 PCIs (12,118 consecutive hospital admissions) performed by 31 cardiologists at two hospitals in New Hampshire and two in Maine and one hospital in Massachusetts supporting these procedures. Operators were categorized into terciles based on annualized volume of procedures. Univariate and multivariate regression analyses were used to control for case-mix. Successful outcomes included angiographic success (all lesions attempted dilated to < 50% residual stenosis) and clinical success (at least one lesion dilated to < 50% residual stenosis and no adverse outcomes). In-hospital adverse outcomes included coronary artery bypass graft surgery (CABG), myocardial infarction (MI) and death. RESULTS After adjustment for case-mix, higher angiographic (low, middle and high terciles: 84.7%, 86.1% and 90.3%, p-trend 0.006) and clinical success rates (85.8%, 88.0% and 90.7%, p-trend 0.025), with fewer referrals to CABG (4.54%, 3.75% and 2.49%, p-trend <0.001), were seen as operator volume increased. There was a trend toward higher MI rates for high volume operators (2.00%, 1.98% and 2.57%, p-trend 0.06); all terciles had similar in-hospital mortality rates (1.09%, 0.96% and 1.05%, p-trend 0.8). CONCLUSIONS There is a significant relation between operator volume and outcomes in PCIs. Efforts should be directed toward understanding why high volume operators are more successful and encounter fewer adverse outcomes.Objectives. We sought to determine whether there is a relation between operator volume and outcomes for percutaneous coronary interventions (PCIs). Background. A 1993 American College of Cardiology/American Heart Association task force stated that cardiologists should perform ≥75 procedures/year to maintain competency in PCIs; however, there were limited data available to support this statement. Methods. Data were collected from 1990 through 1993 on 12,988 PCIs (12,118 consecutive hospital admissions) performed by 31 cardiologists at two hospitals in New Hampshire and two in Maine and one hospital in Massachusetts supporting these procedures. Operators were categorized into terciles based on annualized volume of procedures. Univariate and multivariate regression analyses were used to control for case-mix. Successful outcomes included angiographic success (all lesions attempted dilated to <50% residual stenosis) and clinical success (at least one lesion dilated to <50% residual stenosis and no adverse outcomes). In-hospital adverse outcomes included coronary artery bypass graft surgery (CABG), myocardial infarction (MI) and death. Results. After adjustment for case-mix, higher angiographic (low, middle and high terciles: 84.7%, 86.1% and 90.3%, p-trend 0.006) and clinical success rates (85.8%, 88.0% and 90.7%, p-trend 0.025), with fewer referrals to CABG (4.54%, 3.75% and 2.49%, p-trend <0.001), were seen as operator volume increased. There was a trend toward higher MI rates for high volume operators (2.00%, 1.98% and 2.57%, p-trend 0.06); all terciles had similar in-hospital mortality rates (1.09%, 0.96% and 1.05%, p-trend 0.8). Conclusions. There is a significant relation between operator volume and outcomes in PCIs. Efforts should be directed toward understanding why high volume operators are more successful and encounter fewer adverse outcomes.

Prognostic value of dobutamine stress technetium-99m-sestamibi single-photon emission computed tomography myocardial perfusion imaging: stratification of a high-risk population

OBJECTIVES This work was undertaken to define the intrinsic cardiac risk of the patient population referred for dobutamine stress perfusion imaging and to determine whether dobutamine technetium-99m ((99m)Tc)-sestamibi single-photon emission computed tomography (SPECT) imaging is capable of risk stratification in this population. BACKGROUND In animal models, dobutamine attenuates the myocardial uptake of (99m)Tc-sestamibi resulting in underestimation of coronary stenoses. Therefore, we hypothesized that the prognostic value of dobutamine stress (99m)Tc-sestamibi SPECT myocardial perfusion imaging might be impaired, owing to reduced detection of coronary stenoses. METHODS We reviewed the clinical outcome of 308 patients (166 women, 142 men) who underwent dobutamine stress SPECT (99m)Tc-sestamibi imaging at our institution from September 1992 through December 1996. RESULTS During an average follow-up of 1.9 +/- 1.1 years, there were 33 hard cardiac events (18 myocardial infarctions [MI] and 15 cardiac deaths) corresponding to an annual cardiac event rate of 5.8%/year, which is significantly higher than the event rate for patients referred for exercise SPECT imaging at our institution (2.2%/year). Event rates were higher after an abnormal dobutamine (99m)Tc-sestamibi SPECT study (10.0%/year) than after a normal study (2.3%/year) (p < 0.01), even after adjusting for clinical variables. In the subgroup (n = 29) with dobutamine-induced ST-segment depression and abnormal SPECT imaging, the prognosis was poor, with annual cardiac death and nonfatal MI rates of 7.9% and 13.2%, respectively. CONCLUSIONS Patients referred for dobutamine perfusion imaging are a high-risk population, and dobutamine stress (99m)Tc-sestamibi SPECT imaging is capable of risk stratification in these patients.

Changing outcomes in percutaneous coronary interventions: A study of 34,752 procedures in Northern New England, 1990 to 1997

OBJECTIVES We sought to evaluate the changing outcomes of percutaneous coronary interventions (PCIs) in recent years. BACKGROUND The field of interventional cardiology has seen considerable growth in recent years, both in the number of patients undergoing procedures and in the development of new technology. In view of recent changes, we evaluated the experience of a large, regional registry of PCIs and outcomes over time. METHODS Data were collected from 1990 to 1997 on 34,752 consecutive PCIs performed at all hospitals in Maine (two), New Hampshire (two) and Vermont (one) supporting these procedures, and one hospital in Massachusetts. Univariate and multivariate regression analyses were used to control for case mix. Clinical success was defined as at least one lesion dilated to <50% residual stenosis and no adverse outcomes. In-hospital adverse outcomes included coronary artery bypass graft surgery (CABG), myocardial infarction and mortality. RESULTS Over time, the population undergoing PCIs tended to be older with increasing comorbidity. After adjustment for case mix, clinical success continued to improve from a low of 88.2% in earlier years to a peak of 91.9% in recent years (p trend <0.001). The rate of emergency CABG after PCI fell in recent years from a peak of 2.3% to 1.3% (p trend <0.001). Mortality rates decreased slightly from 1.2% to 1.1% (p trend 0.007). CONCLUSIONS There has been a significant improvement in clinical outcomes for patients undergoing PCIs in northern New England, including a significant decline in the need for emergency CABG.

Cause of in-hospital death in 12,232 consecutive patients undergoing percutaneous transluminal coronary angioplasty ☆ ☆☆

BACKGROUND Some deaths after percutaneous coronary angioplasty (PTCA) occur in high-risk situations (eg, shock), whereas others are unexpected and related to procedural complications. To better describe the epidemiologic causes of death after PTCA, we undertook a systematic review of all in-hospital PTCA deaths in Northern New England from 1990 to 1993. METHODS The medical records of 121 patients who died during their acute hospitalization for PTCA were reviewed with a standardized data extraction tool to determine a mode of death (eg, low output failure, arrhythmia, respiratory failure) and a circumstance of death (eg, death attributable to a procedural complication, preexisting acute cardiac disease). Any death not classified as a procedural complication was reviewed by a committee and the circumstance of death assigned by a majority rule. RESULTS Low-output failure was the most common mode of death occurring in 80 (66.1%) of 121 patients. Other modes of death included ventricular arrhythmias (10.7%), stroke (4.1%), preexisting renal failure (4.1%), bleeding (2.5%), ventricular rupture (2.5%), respiratory failure (2.5%), pulmonary embolism (1.7%), and infection (1.7%). The circumstance of death was a procedural complication in 65 patients (53.7%) and a preexisting acute cardiac condition in 41 patients (33.9%). Women were more likely to die of a procedural complication than were men. CONCLUSION Procedural complications account for half of all post-PTCA deaths and are a particular problem for women. Other deaths are more directly related to patient acuity or noncardiac, comorbid conditions. Understanding why women face an increased risk of procedural complications may lead to improved outcomes for all patients.