Waqar H. Ahmed

Treatment with Bivalirudin (Hirulog) as Compared with Heparin during Coronary Angioplasty for Unstable or Postinfarction Angina

BACKGROUND Heparin is often administered during and after coronary angioplasty to prevent closure of the dilated vessel. However, ischemic or hemorrhagic complications occur in 5 to 10 percent of treated patients. We studied whether these complications could be prevented when the direct thrombin inhibitor bivalirudin (Hirulog) was used in place of heparin. METHODS We performed a double-blind, randomized trial in 4098 patients undergoing angioplasty for unstable or postinfarction angina. Patients were assigned to receive either heparin or bivalirudin immediately before angioplasty. The primary end point were death in the hospital, myocardial infarction, abrupt vessel closure, or rapid clinical deterioration of cardiac origin. RESULTS In the total study group, bivalirudin did not significantly reduce the incidence of the primary end point (11.4 percent, vs. 12.2 percent for heparin) but did result in a lower incidence of bleeding (3.8 percent vs. 9.8 percent, P < 0.001). In the prospectively stratified subgroup of 704 patients with postinfarction angina, bivalirudin therapy resulted in a lower incidence of the primary end point (9.1 percent vs. 14.2 percent, P = 0.04) and a lower incidence of bleeding (3.0 percent vs. 11.1 percent, P < 0.001), but in a similar cumulative rate of death, myocardial infarction, and repeated revascularization in the six months after angioplasty (20.5 percent vs. 25.1 percent, P = 0.17). CONCLUSIONS Bivalirudin was at least as effective as high-dose heparin in preventing ischemic complications in patients who underwent angioplasty for unstable angina, and it carried a lower risk of bleeding. Bivalirudin, as compared with heparin, reduced the risk of immediate ischemic complications in patients with postinfarction angina, but this difference was no longer apparent after six months.

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.

Relation between clinical presentation and angiographic findings in unstable angina pectoris, and comparison with that in stable angina

The diagnosis of unstable angina encompasses a broad spectrum of patients with myocardial ischemia, varying widely in cause, prognosis and responsiveness to therapy. A new clinical classification of unstable angina is based on the following 2 components: severity, and the clinical setting in which unstable angina develops. The hypothesis that this clinical classification correlates with the underlying coronary artery anatomy was tested. In 238 consecutive patients, an unstable angina score ranging from 2 to 6 was determined by adding the scores for severity (1 = unstable angina without pain at rest; 2 = pain at rest > 48 hours before angiography; and 3 = pain at rest < or = 48 hours before angiographic evaluation) and the clinical setting of unstable angina (1 = unstable angina secondary to a noncardiac condition; 2 = primary unstable angina; and 3 = early postinfarction unstable angina). Fifty concurrently studied consecutive patients with stable angina were assigned a score of 0. Patients with unstable angina averaged 63 +/- 11 years of age, and 165 were men (69%). Pain at rest occurred in 202 of 238 patients (85%), and angiography was performed < or = 48 hours in 139 of these patients (69%). Among patients with unstable angina, 5 (2%) had secondary unstable angina, 143 (60%) had primary unstable angina, and 90 (38%) had postinfarction unstable angina. Multivariable regression analysis identified the unstable angina score as the most important predictor of intracoronary thrombus (p = 0.011) and lesion complexity (p = 0.004) in the ischemia-related artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Excimer laser-facilitated angioplasty for undilatable coronary narrowings

Calcified and fibrotic coronary artery lesions cannot always be dilated with conventional balloon angioplasty even at high pressures. This study examines the success of excimer laser facilitated angioplasty in 38 lesions in 37 patients with lesions that failed balloon angioplasty alone.

Relation between abrupt vessel closure and the anticoagulant response to heparin or bivalirudin during coronary angioplasty

The dosing of anticoagulants during coronary angioplasty is commonly guided by measurements of activated clotting time (ACT), but the usefulness of these measurements remains uncertain. The Hirulog Angioplasty Study was a randomized, double-blind comparison of heparin versus bivalirudin in 4,312 patients undergoing angioplasty for unstable or postinfarction angina. In 4,098 of the patients randomized, the balloon was inflated. All patients had ACT measurements 5 minutes after a weight-adjusted bolus of heparin or bivalirudin, and patients undergoing complicated or prolonged angioplasty procedures lasting >45 minutes had additional ACT measurements to guide further anticoagulant therapy. The analysis presented in this article evaluated the relation between the initial or maximum ACT measurements and the risk of abrupt vessel closure during heparin or bivalirudin therapy. Abrupt vessel closure occurred in 189 of 2,039 patients (9.3%) treated with heparin, and in 189 of 2,059 patients (9.2%) treated with bivalirudin (p = not significant). An inverse relation between the risk of abrupt closure and initial ACT measurements was observed in heparin-treated patients: the probability of abrupt vessel closure decreased by 1.3% for every 10-second increase in the initial ACT response to heparin therapy (p = 0.02). Among 903 of 2,039 heparin-treated patients (44%) who received additional heparin for prolonged or complicated procedures, the likelihood of abrupt vessel closure also decreased by 1.1% for every 10-second increase in ACT (p = 0.04). In 2,059 patients treated with bivalirudin, however, no relation between the probability of abrupt vessel closure and the initial ACT measurement was observed (p = 0.88). From the results it was concluded that when heparin is used during coronary angioplasty, the risk of abrupt vessel closure is related to patient responsiveness to anticoagulation therapy. Heparin-resistant patients are more likely to experience abrupt vessel closure than patients who have high ACT values in response to initial therapy. In contrast, when bivalirudin is used during coronary angioplasty, a flat relation between the risk of abrupt vessel closure and ACT values is seen. This suggests that the direct thrombin inhibitor, bivalirudin, provides more even levels of anticoagulation and more predictable levels of risk of abrupt closure than heparin. Measurements of ACT may not be necessary when bivalirudin is used during coronary angioplasty.

Bivalirudin Compared With Heparin During Coronary Angioplasty for Thrombus-Containing Lesions

OBJECTIVES We investigated whether bivalirudin is more effective than heparin in preventing ischemic complications in high risk patients undergoing coronary angioplasty for thrombus-containing lesions detected by angiography. BACKGROUND Heparin is administered during coronary angioplasty to prevent closure of the dilated vessel. Bivalirudin (Hirulog) is a direct thrombin inhibitor that can be safely substituted for heparin during angioplasty. Bivalirudin has several theoretic advantages over heparin as an anticoagulant agent. METHODS We performed an observational analysis of the Hirulog Angioplasty Study in which 4,098 patients with unstable or postinfarction angina were randomized to receive either bivalirudin or heparin during coronary angioplasty. The study group for this analysis consisted of 567 patients who had thrombus-containing lesions on angiography. The primary end point was death, myocardial infarction, emergency coronary artery bypass graft surgery or abrupt vessel closure before hospital discharge. RESULTS Patients with thrombus-containing lesions had a higher incidence of myocardial infarction (5.1% vs. 3.2%, p = 0.03) and abrupt vessel closure (13.6% vs. 8.3%, p < 0.001) than those without thrombus. In patients with thrombus-containing lesions, however, the incidence of the primary end point was not different between the bivalirudin and heparin treatment groups. Furthermore, no difference in the incidence of ischemic events at 6 months was seen between the treatment groups. CONCLUSIONS Bivalirudin is not more effective than heparin in preventing ischemic complications in patients undergoing coronary angioplasty for thrombus-containing lesions detected by angiography. Other approaches, perhaps involving potent anti-platelet agents, should be considered for patients with thrombus-containing lesions.

Glomerular filtration rate estimated by the CKD-EPI formula is a powerful predictor of in-hospital adverse clinical outcomes after an acute coronary syndrome.

The prognostic value of admission estimated glomerular filtration rate (eGFR) calculated by the new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula for cardiovascular adverse outcomes in acute coronary syndrome (ACS) was explored. Baseline eGFR was classified as no renal dysfunction (>90 mL/min per 1.73 m2), borderline (90-60.1 mL/min per 1.73 m2), moderate (60-30.1 mL/min per 1.73 m2), or severe (≤30 mL/min per 1.73 m2) renal dysfunction. Of the 5034 patients, 3415 (67.8%) had eGFR <90. Compared to patients with an eGFR ≥60 mL/min per 1.73 m2, patients with <60 mL/min per 1.73 m2 were less likely to be treated with β-blockers, angiotensin-converting enzyme inhibitors, or statins, or to undergo percutaneous coronary interventions. Lower eGFR showed a stepwise association with significantly worse adverse in-hospital outcomes. The adjusted odds ratio of in-hospital death with an eGFR <30 mL/min per 1.73 m2 was 3.1 (95% confidence interval 1.1-8.4, P = .0324), compared with an eGFR >90 mL/min per 1.73 m2. Estimated glomerular filtration rate calculated by the new CKD-EPI is an independent predictor of major adverse cardiac outcomes in patients with ACS.

Review of the TAXUS® Liberté™ SR paclitaxel-eluting coronary stent

The advent of drug-eluting stents has revolutionized the treatment of coronary heart disease. Interventional cardiologists are increasingly treating more complex lesions in patients that would have otherwise required bypass surgery. As a result of technological advances, the second-generation thin strut TAXUS stent – the TAXUS® Liberté™ SR paclitaxel-eluting coronary stent – has now been introduced into routine clinical practice. The Liberté stent has evolved from the currently available TAXUS Express™ stent to provide enhanced lesion access in challenging anatomies as well as more uniform drug delivery. This article will provide an overview of the TAXUS Liberté stent.

The cardiac patient during Ramadan and Hajj.

The holy month of Ramadan is one of the five pillars of Islam. During this month, fasting Muslims refrain from eating, drinking, smoking, and sex from dawn until sunset. Although the Quran exempts sick people from the duty of fasting, it is not uncommon for many heart disease patients to fast during Ramadan. Despite the fact that more than a billion Muslims worldwide fast during Ramadan, there is no clear consensus on its effects on cardiac disease. Some studies have shown that the effects of fasting on stable patients with cardiac disease are minimal and the majority of patients with stable cardiac illness can endure Ramadan fasting with no clinical deterioration. Fasting during Ramadan does not seem to increase hospitalizations for congestive heart failure. However, patients with decompensated heart failure or those requiring large doses of diuretics are strongly advised not to fast, particularly when Ramadan falls in summer. Patients with controlled hypertension can safely fast. However, patients with resistant hypertension should be advised not to fast until their blood pressure is reasonably controlled. Patients with recent myocardial infarction, unstable angina, recent cardiac intervention or cardiac surgery should avoid fasting. Physician advice should be individualized and patients are encouraged to seek medical advice before fasting in order to adjust their medications, if required. The performance of the Hajj pilgrimage is another pillar of Islam and is obligatory once in the lifetime for all adult Muslims who are in good health and can afford to undertake the journey. Hajj is a physically, mentally, emotionally, and spiritually demanding experience. Medical checkups one or two months before leaving for Hajj is warranted, especially for those with chronic illnesses such as cardiovascular disease. Patients with heart failure, uncontrolled hypertension, serious arrhythmias, unstable angina, recent myocardial infarction, or cardiac surgery should be considered unfit for undertaking the Hajj pilgrimage.

Effect of Comorbidity On Unplanned Readmissions After Percutaneous Coronary Intervention (From The Nationwide Readmission Database)

It is unclear how comorbidity influences rates and causes of unplanned readmissions following percutaneous coronary intervention (PCI). We analyzed patients in the Nationwide Readmission Database who were admitted to hospital between 2010 and 2014. The comorbidity burden as defined by the Charlson Comorbidity Index (CCI). Primary outcomes were 30-day readmission rates and causes of readmission according to comorbidity burden. A total of 2,294,346 PCI procedures were included the analysis. The patients in CCI = 0, 1, 2 and ≥3 were 842,272(36.7%), 701,476(30.6%), 347,537(15.1%) and 403,061(17.6%), respectively. 219,227(9.6%) had an unplanned readmission within 30 days and rates by CCI group were 6.6%, 8.6%, 11.4% and 15.9% for CCI groups 0, 1, 2 and ≥3, respectively. The CCI score was also associated with greater cost (cost of index PCI for not readmitted vs readmitted was CCI = 0