Samuel J. Shubrooks

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.

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.

Complications and long-term outcome after percutaneous coronary angioplasty in chronic hemodialysis patients

The objective of this investigation was to assess the acute and long-term outcome after coronary angioplasty in patients undergoing chronic hemodialysis. Previous studies have suggested a high incidence of restenosis after coronary angioplasty performed in patients with renal failure. Medical discharge abstracts for 8342 patients undergoing angioplasty during a 5-year period were searched to identify all coronary angioplasty procedures performed in patients undergoing chronic hemodialysis. Procedural and follow-up coronary angiograms were reviewed in a core angiographic laboratory. Hospital records and office visit notes were obtained to assess acute and long-term outcome. Twenty-one patients undergoing chronic hemodialysis had been treated by coronary angioplasty. The 9 men and 12 women had a mean age of 59 +/- 10 years (range 37 to 78 years) and had been undergoing hemodialysis for 6.2 +/- 6.4 years (range 1 to 19 years). Procedural success was achieved in 12 (57%) of 21 patients. Three (14%) patients died; 4 suffered nonfatal myocardial infarctions (19%); 1 (5%) required emergency bypass surgery; and 1 (5%) had abrupt vessel closure without complications. Of the 15 (71%) patients who were discharged with a patent angioplasty vessel, 4 (27%) died and 9 (60%) had recurrence of angina within 1 year. Of 9 patients with recurrent angina, 7 underwent a second angiography, and all showed evidence of restenosis at the previous angioplasty site. The results of coronary angioplasty in these 21 hemodialysis patients suggest a high rate of acute complications and poor long-term prognosis in this subgroup. Other strategies for revascularization should be considered for these patients.

Percutaneous transluminal coronary angioplasty in the elderly: Epidemiology, clinical risk factors, and in-hospital outcomes☆☆☆★

Objectives To explore the relation between older age and clinical presentation, procedural success, and in-hospital outcomes among a large unselected population undergoing percutaneous transluminal coronary angioplasty (PTCA). Background Although more elderly patients are receiving PTCA, studies of post-PTCA outcomes among the elderly have been limited by small numbers and exclusive selection criteria. Methods Data were collected as a part of a prospective registry of all percutaneous coronary interventions performed in Maine, New Hampshire, and from 1 institution in Massachusetts between October 1989 and December 1993. Comparisons across 4 age groups, (<60, 60 to 69, 70 to 79, and 80 years and above) were performed using chi-square tests, the Mantel-Haenzsel test for trend, and logistic regression. Results Twelve thousand one hundred seventy-two hospitalizations for PTCA were performed with 507 of them (4%) in persons at least 80 years old. Octogenarians were more likely to be women, have multivessel disease, high-grade stenoses, and complex lesions but were less likely to have hypercholesterolemia, a history of smoking, or have undergone a previous PTCA. In the elderly, PTCAs were more often performed urgently and for unstable syndromes compared with younger age groups. Advancing age is strongly associated with in-hospital death, and among the oldest old with an increased risk of postprocedural myocardial infarction. Despite differing presentation and procedural priority, angiographic success and subsequent bypass surgery did not vary by age. Conclusions With the increasing age of the population at large as well as that segment at risk for cardiac revascularization, information about age-associated risks of the procedure, especially the substantially higher risk of death in octogenarians, will be critical for both physicians and patients considering PTCA. (Am Heart J 1999;137:639-45.)

Frequency, risk factors, and outcome for bacteremia after percutaneous transluminal coronary angioplasty

The objectives of this study were to examine bacteremias after percutaneous transluminal coronary angioplasty (PTCA) with respect to incidence, outcome, and risk factors. Patients undergoing PTCA from January 1990 through April 1994 were studied; during this period a total of 4,217 PTCAs were performed in 3,473 patients. With use of predefined clinical and microbiologic criteria, bacteremias were divided into 3 categories according to the relation to the PTCA procedure: PTCA-related, unrelated, and indeterminate. Ninety-one patients with at least 1 positive blood culture during a 7-week period after PTCA were identified. The bacteremia was classified as unrelated to the PTCA procedure in 32 patients, PTCA-related in 27, and indeterminant in the remaining 32 patients. The attack rate of PTCA-related bacteremia during the 52-month period was 0.64%. The most common organisms causing PTCA-related bacteremia were Staphylococcus aureus (14 patients), coagulase-negative staphylococci (9 patients) and group B streptococci (6 patients). Septic complications, which included femoral artery mycotic aneurysm, septic arthritis, and septic thrombosis, occurred in 10 patients (0.24%). Independent risk factors for PTCA-related bacteremia included duration of procedure (odds ratio [OR] 2.9; p = 0.04), number of catheterizations at the same site (OR 4.0; p = 0.015), difficult vascular access (OR 14.9; p = 0.007), arterial sheath in place > 1 day (OR 6.8; p = 0.025), congestive heart failure (OR 43.3; p = 0.002). Thus, PTCA-related bacteremia is an infrequent complication of PTCA but can be associated with significant morbidity, particularly when the infecting organism is S. aureus. Four of the 5 risk factors for PTCA-related bacteremia appear to correlate directly with increased vascular injury or maintenance of the arterial entry for the procedure.

The significance of bundle branch block during acute myocardial infarction

Analysis of the course of 71 patients with acute myocardial infarction complicated by bundle branch block (BBB) confirms a high incidence of atrioventricular (A-V) block (42 per cent) and severe pump failure (35 per cent) in these patients. Hospital mortality was not correlated with BBB per se, but rather with the associated development of second or third degree A-V block (57 per cent with A-V block vs. 12 per cent without A-V block; p less than .0005) or severe pump failure (35 per cent with vs. 11 per cent without severe pump failure; p less than .001). However, late mortality was high and not significantly different among those surviving hospitalization whether transient A-V block was present or absent. Eight of 11 late deaths were sudden. Temporary pacing could not be shown to alter hospital survival statistically, but made the onset of complete heart block a hemodynamically smooth and clinically undetectable event in several patients who later survived. The place of permanent pacing in these patients cannot be clearly determined on the basis of this study or in the available literature. More data obtained either by pooling the experience of several centers or from a prospective randomized study are needed to determine the indications for permanent pacemakers.

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.