Faculty Bibliography

Heavier than air flying machines are impossible. Lord Kelvin, President, Royal Society of England, 1895 What is known and Objective: Warfarin, an oral anticoagulant, which has been in clinical use for over sixty years, remains a challenge for clinicians to utilize, given the multiplicity of items which can limit its efficacy. Our objective is to review the evidence and comment on whether INR control can be better than has been currently reported in various studies. Comment: The duration of time a patient's international normalized ratio (INR) is maintained within the therapeutic range (time in the therapeutic range, TTR) for his or her particular indication for the drug impacts the effectiveness and safety of warfarin therapy. Maintaining a therapeutic INR while on warfarin is difficult, and numerous studies employing various strategies confirm the challenge, but not the impossibility of achieving a TTR above 70%. What is new and Conclusion: Maintaining a therapeutic INR requires a dedicated multi-faceted approach. With diligence, skill and various therapeutic strategies, a TTR >70% can be achieved.

BACKGROUND: Although coronary artery bypass graft surgery (CABG) is known to reduce angina, previous studies have suggested that anti-anginal medication use is not significantly reduced after CABG. However, it is unclear how functional testing results have an impact on anti-anginal medication prescription patterns. OBJECTIVES: To determine whether post-CABG functional testing results impact prescription patterns of anti-anginal medication during the 12 months after CABG. METHODS: The Routine versus Selective Exercise Treadmill Testing after Coronary Artery Bypass Graft Surgery (ROSETTA-CABG) Registry is a prospective, multicenter study. We examined anti-anginal medication use (beta blockers, calcium channel blockers and nitrates) at discharge and at 12 months post-CABG with respect to functional testing results among 392 patients. RESULTS: Among the 392 patients, 146 had at least one functional test over the 12-month follow up period. Among the 146 patients, 17% had positive functional tests, 69% had negative tests, and 14% had indeterminate tests. Both beta blocker and calcium channel blocker use did not increase from discharge to 12 months following a positive test (N = 25) (84% vs. 80%; p = NS; 16% vs. 16%; p = NS), while nitrate use increased seven-fold (4% vs. 28%; p = 0.03). However, following a negative test (N = 100), beta blocker use only decreased modestly (85% vs. 70%; p = 0.01), while both calcium channel blocker and nitrate use were unchanged (30% vs. 20%; p = NS; 4% vs. 6%; p = NS, respectively). Following an indeterminate test (N = 21), anti-anginal medication use was unchanged (p = NS for all 3 classes of medication). CONCLUSION: The use of anti-anginal medication is only modestly reduced after CABG, and functional testing results during the first year post-CABG do not have a strong impact on prescription patterns of anti-anginal agents

BACKGROUND: There is little consensus regarding the use of functional testing after coronary artery bypass graft surgery (CABG). Some physicians opt for a routine functional testing strategy, while others employ a symptom-driven strategy. OBJECTIVE: To examine the effects of routine post-CABG functional testing on the use of follow-up cardiac procedures and clinical events. METHODS: The Routine versus Selective Exercise Treadmill Testing after Coronary Artery Bypass Graft Surgery (ROSETTA-CABG) Registry is a prospective, multicenter cohort study examining the use of functional testing after CABG among 408 patients. The frequencies of functional testing, cardiac procedures, and clinical events were examined during the first 12 months following a successful CABG. RESULTS: Patients were predominantly male (80%) with a mean age of 63 +/- 10 years. During the 12-month follow up, 111 patients were observed to undergo a routine functional testing strategy, while 284 patients underwent a selective strategy. Patients undergoing routine functional testing underwent fewer follow-up cardiac catheterizations, but similar numbers of revascularization procedures (cardiac catheterizations = 0.9% vs. 8.1%; p = 0.027; percutaneous coronary intervention [PCI] = 0.9% vs. 4.6%; p = NS; repeat CABG = 0.0% vs. 0.0%; p = NS, respectively). However, clinical events were less common among patients who underwent routine functional testing including unstable angina (0.0% vs. 6.4%; p = NS), myocardial infarction (MI) (0.0% vs. 2.1%; p = NS), and death (0.9% vs. 1.4%; p = NS). The majority of clinical and procedural events occurred in the selective group who had a positive functional test (clinical events = 33%; procedural events = 40%). In contrast, no events occurred in patients in the routine group with a positive or indeterminate test, while those with a negative test had more events (6.3%) and procedures (6.3%). CONCLUSIONS: Because routine functional testing 1 year after CABG is associated with extremely low event rates, this strategy does not appear to be warranted

The American College of Cardiology/American Heart Association guidelines for exercise testing do not take a position regarding the utility of routine stress testing after coronary artery bypass grafting (CABG). Our purposes were (1) to document the patterns of use of stress testing after CABG and (2) to establish whether the choice of stress testing strategy is associated with clinical characteristics of patients. The Routine versus Selective Exercise Treadmill Testing after Coronary Artery Bypass Graft Surgery (ROSETTA-CABG) Registry is a prospective multicenter study that examined the use of stress testing after CABG among 395 patients at 16 clinical centers in 6 countries. During the 12 months after CABG, 37% of patients underwent stress testing (range across centers 0% to 100%). Among patients who underwent stress testing, 24% had a clinical indication and 76% had it as a routine follow-up. A total of 65% of stress tests involved exercise treadmill testing alone, 17% involved stress nuclear perfusion imaging, 13% involved stress echocardiographic imaging, and 5% involved other types of stress tests, such as positron emission tomographic scans. The first stress test was performed at a median of 13 weeks after CABG, with 20% of patients having second tests at a median of 28 weeks and 6% having additional tests at a median of 34 weeks. Univariate and multivariate analyses demonstrated that the chief determinant of using routine stress testing was the clinical center. In conclusion, these results suggest that there is little consensus on the appropriate use of stress testing soon after CABG. Practice patterns vary widely; poorly diagnostic tests are used routinely; and the clinical center at which the procedure is performed, rather than the clinical characteristics of the patient, determines the use of stress testing after CABG

BACKGROUND: Diabetes mellitus is associated with poorer long-term outcomes following coronary artery bypass graft (CABG) surgery. However, little is known about the impact of diabetes mellitus on outcomes during the first 12 months following CABG. OBJECTIVES: To examine the relationship between diabetes mellitus and outcomes during the 12 months following CABG. METHODS: The Routine versus Selective Exercise Treadmill Testing after Coronary Artery Bypass Grafting (ROSETTA-CABG) Registry is a prospective, multicentre study examining the use of functional testing after CABG surgery. A total of 398 patients who were enrolled in the ROSETTA-CABG Registry were examined. Diabetic status was defined by medication use at discharge. Only patients undergoing a first successful CABG (all ischemic areas thought to be revascularized) were included. RESULTS: Among the 398 patients, 37 (9.3%) were receiving insulin, 67 (16.8%) were receiving oral hypoglycemic agents, and 294 (73.9%) were not receiving insulin or oral hypoglycemic agents. Insulin-treated patients had a higher 12-month incidence of composite clinical events consisting of readmission for unstable angina, myocardial infarction or death than did oral hypoglycemic-treated patients and nondiabetic patients (21.6% versus 4.5% and 6.0%, respectively; P=0.0003). Insulin-treated patients were also more likely to undergo repeat cardiac catheterization than were oral hypoglycemic-treated patients and nondiabetic patients (18.9% versus 8.8% and 7.9%, respectively; P=0.03). After controlling for other variables, use of insulin was independently associated with a composite of adverse clinical events (OR 3.80, 95% CI 1.5 to 9.6, P=0.005). CONCLUSIONS: During the 12-month period after a successful CABG, insulin-treated patients had a higher rate of adverse cardiac events than did patients receiving oral hypoglycemic agents and nondiabetic patients. These results suggest that diabetic patients may benefit from more aggressive surveillance during the first year after CABG surgery

BACKGROUND: Multiple studies have examined whether clinical outcomes are improved by invasive management following non-Q-wave myocardial infarction (NQWMI). However, it remains unclear whether functional status and quality of life are affected by an invasive strategy. METHODS: Following NQWMI, we randomized 88 patients to invasive management vs noninvasive management. The primary end point was functional status assessed at 12 months using maximal endurance exercise treadmill testing measured in metabolic equivalents. Secondary end points included changes in scores between baseline and 12 months on the Duke Activity Status Index, the Seattle Angina Questionnaire, and the Medical Outcomes Study 36-Item Short-Form Survey. RESULTS: Of the 42 patients in the invasive arm, 83% underwent initial angiography. Of the 46 patients in the noninvasive arm, 91% underwent initial stress testing. Inhospital and 12-month revascularization rates were similar in the 2 arms (24% vs 22%, P > or = .99; 31% vs 30%, P > or = .99). Maximal endurance exercise treadmill testing was also similar at 12 months (7.8 vs 6.7 metabolic equivalents, P = .24). Patients in the invasive arm showed improved functional status by mean difference in their Duke Activity Status Index scores (4.3 vs -3.5, P = .04). Improvements in angina-specific quality of life for patients in the invasive arm were demonstrated by the Seattle Angina Questionnaire measures of anginal stability (21.6 vs -5.3, P = .02), anginal frequency (22.9 vs 2.3, P = .02), treatment satisfaction (11.2 vs -10.3, P = .02), and disease perception (24.7% vs 10.9%, P = .07). CONCLUSIONS: Compared with patients undergoing noninvasive management of NQWMI, patients undergoing invasive management have some measures indicative of improved functional status

OBJECTIVE: The objective of this prespecified substudy of the AFFIRM study, in which no differences in survival or event rates were found in patients with atrial fibrillation (AF) randomized to either rate control or rhythm control, was to test the null hypothesis that quality of life (QoL) is equal with rate- versus rhythm-control treatment strategies in AF. METHODS: Fifty-six (25%) of AFFIRM sites were randomly selected to recruit AFFIRM patients for the QoL substudy. Instruments used in the QoL assessment were (1) Perceived Health; (2) the Cantril Ladder of Life; (3) the Short Form 36 survey; (4) the QoL Index; and (5) the Symptom Checklist: Frequency and Severity. Data were collected at baseline, 2 months, 12 months, and annually; data are reported through 4 years of follow-up. RESULTS: Baseline characteristics of the AFFIRM QoL patients (n = 716) were generally similar to those of the rest of AFFIRM patients. Quality-of-life scores were similar in rate- and rhythm-control assignment groups at all time points. Quality-of-life scores were similar whether the actual rhythm was sinus or AF. Scores increased from baseline to subsequent time points similarly for both groups; these improvements were not additive over time. CONCLUSIONS: Quality of life was comparable between rate- and rhythm-control treatment strategies. In addition, QoL was similar with sinus rhythm versus AF. Attempts to improve QoL by restoring sinus rhythm will usually be unsuccessful