2011 ACCF/AHA Focused Update Incorporated Into the ACC/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines

Emergency medicine and hospital medicine: a call for collaboration

BACKGROUND

In the United States, emergency physicians and hospitalists are increasingly responsible for managing hospitalized patients. These specialists share a common practice space and similar shift work schedules. Together they govern decisions about use of the most expensive care setting in medicine--the hospital.

DISCUSSION

Unfortunately, in most institutions there is little collaboration between emergency physicians and hospitalists, resulting in missed opportunities to improve the quality of care and reduce its cost. In this call to action, we challenge emergency physicians and hospitalists to work together to develop protocols for consistent, evidence-based, and expeditious care of patients admitted from the ED; to collaborate in the care of ED patients who can safely be discharged home; to pursue joint quality, hospital leadership, and cost-effectiveness projects; to work in partnership to assure adequate staffing of hospital-based specialists; and to cooperate in the professional, front-line assessment of clinically and fiscally driven policies aimed at assessing the appropriateness of hospital admissions and readmissions.

SUMMARY

Hospital care is increasingly driven by emergency physicians and hospitalists. We envision a vital role for ongoing collaboration between them in achieving the goals of patient care, education, and quality and safety outcomes.

Role for substance p-based nociceptive signaling in progenitor cell activation and angiogenesis during ischemia in mice and in human subjects

BACKGROUND

Pain triggers a homeostatic alarm reaction to injury. It remains unknown, however, whether nociceptive signaling activated by ischemia is relevant for progenitor cells (PC) release from bone marrow. To this end, we investigated the role of the neuropeptide substance P (SP) and cognate neurokinin 1 (NK1) nociceptor in PC activation and angiogenesis during ischemia in mice and in human subjects.

METHODS AND RESULTS

The mouse bone marrow contains sensory fibers and PC that express SP. Moreover, SP-induced migration provides enrichment for PC that express NK1 and promote reparative angiogenesis after transplantation in a mouse model of limb ischemia. Acute myocardial infarction and limb ischemia increase SP levels in peripheral blood, decrease SP levels in bone marrow, and stimulate the mobilization of NK1-expressing PC, with these effects being abrogated by systemic administration of the opioid receptor agonist morphine. Moreover, bone marrow reconstitution with NK1-knockout cells results in depressed PC mobilization, delayed blood flow recovery, and reduced neovascularization after ischemia. We next asked whether SP is instrumental to PC mobilization and homing in patients with ischemia. Human PC express NK1, and SP-induced migration provides enrichment for proangiogenic PC. Patients with acute myocardial infarction show high circulating levels of SP and NK1-positive cells that coexpress PC antigens, such as CD34, KDR, and CXCR4. Moreover, NK1-expressing PC are abundant in infarcted hearts but not in hearts that developed an infarct after transplantation.

CONCLUSIONS

Our data highlight the role of SP in reparative neovascularization. Nociceptive signaling may represent a novel target of regenerative medicine.

Bridging antiplatelet therapy with cangrelor in patients undergoing cardiac surgery: a randomized controlled trial

CONTEXT

Thienopyridines are among the most widely prescribed medications, but their use can be complicated by the unanticipated need for surgery. Despite increased risk of thrombosis, guidelines recommend discontinuing thienopyridines 5 to 7 days prior to surgery to minimize bleeding.

OBJECTIVE

To evaluate the use of cangrelor, an intravenous, reversible P2Y(12) platelet inhibitor for bridging thienopyridine-treated patients to coronary artery bypass grafting (CABG) surgery.

DESIGN, SETTING, AND PATIENTS

Prospective, randomized, double-blind, placebo-controlled, multicenter trial, involving 210 patients with an acute coronary syndrome (ACS) or treated with a coronary stent and receiving a thienopyridine awaiting CABG surgery to receive either cangrelor or placebo after an initial open-label, dose-finding phase (n = 11) conducted between January 2009 and April 2011. Interventions Thienopyridines were stopped and patients were administered cangrelor or placebo for at least 48 hours, which was discontinued 1 to 6 hours before CABG surgery.

MAIN OUTCOME MEASURES

The primary efficacy end point was platelet reactivity (measured in P2Y(12) reaction units [PRUs]), assessed daily. The main safety end point was excessive CABG surgery-related bleeding.

RESULTS

The dose of cangrelor determined in 10 patients in the open-label stage was 0.75 μg/kg per minute. In the randomized phase, a greater proportion of patients treated with cangrelor had low levels of platelet reactivity throughout the entire treatment period compared with placebo (primary end point, PRU <240; 98.8% (83 of 84) vs 19.0% (16 of 84); relative risk [RR], 5.2 [95% CI, 3.3-8.1] P < .001). Excessive CABG surgery-related bleeding occurred in 11.8% (12 of 102) vs 10.4% (10 of 96) in the cangrelor and placebo groups, respectively (RR, 1.1 [95% CI, 0.5-2.5] P = .763). There were no significant differences in major bleeding prior to CABG surgery, although minor bleeding episodes were numerically higher with cangrelor.

CONCLUSIONS

Among patients who discontinue thienopyridine therapy prior to cardiac surgery, the use of cangrelor compared with placebo resulted in a higher rate of maintenance of platelet inhibition.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00767507.

Association of proton pump inhibitor use on cardiovascular outcomes with clopidogrel and ticagrelor: insights from the platelet inhibition and patient outcomes trial

BACKGROUND

The clinical significance of the interaction between clopidogrel and proton pump inhibitors (PPIs) remains unclear.

METHODS AND RESULTS

We examined the relationship between PPI use and 1-year cardiovascular events (cardiovascular death, myocardial infarction, or stroke) in patients with acute coronary syndrome randomized to clopidogrel or ticagrelor in a prespecified, nonrandomized subgroup analysis of the Platelet Inhibition and Patient Outcomes (PLATO) trial. The primary end point rates were higher for individuals on a PPI (n=6539) compared with those not on a PPI (n=12 060) at randomization in both the clopidogrel (13.0% versus 10.9%; adjusted hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.04-1.38) and ticagrelor (11.0% versus 9.2%; HR, 1.24; 95% CI, 1.07-1.45) groups. Patients on non-PPI gastrointestinal drugs had similar primary end point rates compared with those on a PPI (PPI versus non-PPI gastrointestinal treatment: clopidogrel, HR, 0.98; 95% CI, 0.79-1.23; ticagrelor, HR, 0.89; 95% CI, 0.73-1.10). In contrast, patients on no gastric therapy had a significantly lower primary end point rate (PPI versus no gastrointestinal treatment: clopidogrel, HR, 1.29; 95% CI, 1.12-1.49; ticagrelor, HR, 1.30; 95% CI, 1.14-1.49).

CONCLUSIONS

The use of a PPI was independently associated with a higher rate of cardiovascular events in patients with acute coronary syndrome receiving clopidogrel. However, a similar association was observed between cardiovascular events and PPI use during ticagrelor treatment and with other non-PPI gastrointestinal treatment. Therefore, in the PLATO trial, the association between PPI use and adverse events may be due to confounding, with PPI use more of a marker for, than a cause of, higher rates of cardiovascular events.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT00391872.

Thrombin-receptor antagonist vorapaxar in acute coronary syndromes

BACKGROUND

Vorapaxar is a new oral protease-activated-receptor 1 (PAR-1) antagonist that inhibits thrombin-induced platelet activation.

METHODS

In this multinational, double-blind, randomized trial, we compared vorapaxar with placebo in 12,944 patients who had acute coronary syndromes without ST-segment elevation. The primary end point was a composite of death from cardiovascular causes, myocardial infarction, stroke, recurrent ischemia with rehospitalization, or urgent coronary revascularization.

RESULTS

Follow-up in the trial was terminated early after a safety review. After a median follow-up of 502 days (interquartile range, 349 to 667), the primary end point occurred in 1031 of 6473 patients receiving vorapaxar versus 1102 of 6471 patients receiving placebo (Kaplan-Meier 2-year rate, 18.5% vs. 19.9%; hazard ratio, 0.92; 95% confidence interval [CI], 0.85 to 1.01; P=0.07). A composite of death from cardiovascular causes, myocardial infarction, or stroke occurred in 822 patients in the vorapaxar group versus 910 in the placebo group (14.7% and 16.4%, respectively; hazard ratio, 0.89; 95% CI, 0.81 to 0.98; P=0.02). Rates of moderate and severe bleeding were 7.2% in the vorapaxar group and 5.2% in the placebo group (hazard ratio, 1.35; 95% CI, 1.16 to 1.58; P<0.001). Intracranial hemorrhage rates were 1.1% and 0.2%, respectively (hazard ratio, 3.39; 95% CI, 1.78 to 6.45; P<0.001). Rates of nonhemorrhagic adverse events were similar in the two groups.

CONCLUSIONS

In patients with acute coronary syndromes, the addition of vorapaxar to standard therapy did not significantly reduce the primary composite end point but significantly increased the risk of major bleeding, including intracranial hemorrhage. (Funded by Merck; TRACER ClinicalTrials.gov number, NCT00527943.).

Risk stratification in acute coronary syndromes

Accurate and readily available systems for risk stratification and a wide array of antithrombotic agents, on top of classical anti-ischemic drugs, provide the noninvasive cardiologist admitting the patient in the CCU with an effective and reliable armamentarium for the safe management of most patients with ACS. From the interventionalist's perspective, the immediate knowledge of the coronary anatomy yields the most valuable information to address the most appropriate treatment. The sooner angiography is performed the higher the benefit for patients at moderate to high risk, but if performed by expert teams and with the correct use of modern drugs and devices, the invasive approach has the potential to reduce costs and length of hospital stay also in low-risk patients. Although still some reluctance remains to equalize treatment strategies for patients with STEMI to those with NSTEMI, such differences will likely disappear in the near future with upcoming new evidence. Cardiac surgery may represent a life-saving alternative for patients presenting with NSTEMI evolving in cardiogenic shock or with mechanical complications, or in patients unsuitable for PCI or with failed PCI attempts. In stabilized conditions after the treatment of the culprit lesion, patients with severe multivessel disease may benefit from cardiac surgery to complete myocardial revascularization. Indications for CABG in this setting should be evaluated in the context of a local "heart team" or through prespecified protocols in centers without cardiac surgery on site.

Heart failure and non-ST-segment elevation myocardial infarction: a review for a widespread situation

Up to 15% of patients with NSTEMI present at admission with heart failure. Scientific evidence for its management is limited but much progress has been made during the last years. Our purpose was to review the last data concerning heart failure in NSTEMI and perform an update on the subject, with the following findings as main highlights. As Killip classes III and IV, Killip class II onset in the context of NSTEMI has also proven bad prognosis significance. Beta-blocker therapy has proven benefit to patients with Killip class II in observational studies and small trials. Angiotensin-converting enzyme inhibitor therapy shows stronger evidence of benefit in patients with heart failure than in patients without it. Eplerenone is indicated for patients with left ventricular dysfunction and heart failure or diabetes mellitus. Implantable cardioverter defibrillators improve survival in patients with severe ventricular dysfunction after a myocardial infarction. Cardiac resynchronization therapy indications must be carefully assessed due to the high rate of implants that do not fulfill guidelines indications. In conclusion, heart failure during a NSTEMI is a common and meaningful situation which warrants careful management and further investigation to reach stronger evidence for clinical recommendations.

Secondary prevention of hyperkalemia with sodium polystyrene sulfonate in cardiac and kidney patients on renin-angiotensin-aldosterone system inhibition therapy

BACKGROUND

Hyperkalemia, induced by renin-angiotensin-aldosterone system inhibition (RAAS-I) in patients with chronic kidney disease (CKD), or cardiac disease often leads to withdrawal of RAAS-I therapy. Sodium polystyrene sulfonate (SPS) is a potassium-binding resin used for the treatment of hyperkalemia. Recently, concerns about the safety and efficacy of SPS were raised. We report here a follow-up of 14 patients with CKD and heart disease on RAAS-I treatment who were treated with low-dose daily SPS to prevent recurrence of hyperkalemia.

HYPOTHESIS

Daily SPS is safe and effective for secondary prevention of hyperkalemia induced by RAAS-I therapy in CKD patients with heart disease.

METHODS

We reviewed the medical charts of the patients with CKD (nondialysis patients) and heart disease treated in our CKD clinic from 2005 to 2010 and identified all patients on RAAS-I therapy who were treated with daily SPS (sorbitol-free) after episodes of hyperkalemia. Data on hospitalizations, symptoms that may be attributed to SPS therapy, and electrolyte concentration levels were obtained.

RESULTS

Fourteen patients were treated with low-dose SPS therapy for a total of 289 months (median length of follow-up, 14.5 months). None of the patients developed colonic necrosis or life-threatening events that could be attributed to SPS use. Mild hypokalemia was noted in 2 patients and responded to reducing the dose of SPS. No further episodes of hyperkalemia were recorded while patients were on the therapy. SPS was well-tolerated during the follow-up without need for withdrawal or reduction of the dose of RAAS-I therapy by any patients.

CONCLUSIONS

Low-dose SPS was safe and effective as a secondary preventive measure for hyperkalemia induced by RAAS-I in CKD patients with heart disease.

RUBY-1: a randomized, double-blind, placebo-controlled trial of the safety and tolerability of the novel oral factor Xa inhibitor darexaban (YM150) following acute coronary syndrome

AIMS

To establish the safety, tolerability and most promising regimen of darexaban (YM150), a novel, oral, direct factor Xa inhibitor, for prevention of ischaemic events in acute coronary syndrome (ACS).

METHODS

In a 26-week, multi-centre, double-blind, randomized, parallel-group study, 1279 patients with recent high-risk non-ST-segment or ST-segment elevation ACS received one of six darexaban regimens: 5 mg b.i.d., 10 mg o.d., 15 mg b.i.d., 30 mg o.d., 30 mg b.i.d., or 60 mg o.d. or placebo, on top of dual antiplatelet treatment. Primary outcome was incidence of major or clinically relevant non-major bleeding events. The main efficacy outcome was a composite of death, stroke, myocardial infarction, systemic thromboembolism, and severe recurrent ischaemia.

RESULTS

Bleeding rates were numerically higher in all darexaban arms vs. placebo (pooled HR: 2.275; 95% CI: 1.13-4.60, P = 0.022). Using placebo as reference (bleeding rate 3.1%), there was a dose-response relationship (P = 0.009) for increased bleeding with increasing darexaban dose (6.2, 6.5, and 9.3% for 10, 30, and 60 mg daily, respectively), which was statistically significant for 30 mg b.i.d. (P = 0.002). There was no decrease (indeed a numerical increase in the 30 and 60 mg dose arms) in efficacy event rates with darexaban, but the study was underpowered for efficacy. Darexaban showed good tolerability without signs of liver toxicity.

CONCLUSIONS

Darexaban when added to dual antiplatelet therapy after ACS produces an expected dose-related two- to four-fold increase in bleeding, with no other safety concerns but no signal of efficacy. Establishing the potential of low-dose darexaban in preventing major cardiac events after ACS requires a large phase III trial. ClinicalTrials.gov Identifier: NCT00994292.

Aspirin has little additional anti-platelet effect in healthy volunteers receiving prasugrel

BACKGROUND

Strong P2Y(12) blockade, as can be achieved with novel anti-platelet agents such as prasugrel, has been shown in vitro to inhibit both ADP and thromboxane A(2) -mediated pathways of platelet aggregation, calling into question the need for the concomitant use of aspirin.

OBJECTIVE

The present study investigated the hypothesis that aspirin provides little additional anti-aggregatory effect in a group of healthy volunteers taking prasugrel. STUDY PARTICIPANTS/METHODS: In all, 9 males, aged 18 to 40 years, enrolled into the 21-day study. Prasugrel was loaded at 60 mg on day 1 and maintained at 10 mg until day 21. At day 8, aspirin 75 mg was introduced and the dose increased to 300 mg on day 15. On days 0, 7, 14 and 21, platelet function was assessed by aggregometry, response to treatments was determined by VerifyNow and urine samples were collected for quantification of prostanoid metabolites.

RESULTS

At day 7, aggregation responses to a range of platelet agonists were reduced and there was only a small further inhibition of aggregation to TRAP-6, collagen and epinephrine at days 14 and 21, when aspirin was included with prasugrel. Urinary prostanoid metabolites were unaffected by prasugrel, and were reduced by the addition of aspirin, independent of dose.

CONCLUSIONS

In healthy volunteers, prasugrel produces a strong anti-aggregatory effect, which is little enhanced by the addition of aspirin. The addition of aspirin as a dual-therapy with potent P2Y(12) receptor inhibitors warrants further investigation.

Consensus document: antithrombotic therapy in patients with atrial fibrillation undergoing coronary stenting. A North-American perspective

The optimal regimen of the anticoagulant and antiplatelet therapies in patients with atrial fibrillation who have had a coronary stent is unclear. It is well recognised that "triple therapy" with aspirin, clopidogrel, and warfarin is associated with an increased risk of bleeding. National guidelines have not made specific recommendations given the lack of adequate data. In choosing the best antithrombotic options for a patient, consideration needs to be given to the risks of stroke, stent thrombosis and major bleeding. This document describes these risks, provides specific recommendations concerning vascular access, stent choice, concomitant use of proton-pump inhibitors and the use and duration of triple therapy following stent placement based upon the risk assessment.

Cardiovascular disease in the elderly

The aging of the population worldwide will result in increasing numbers of elderly patients, among whom heart disease is the leading cause of death. Changes in cardiovascular physiology with normal aging and prevalent comorbidities result in differences in the effects of common cardiac problems as well as the response to their treatments. Patient-centered goals of care such as maintenance of independence and reduction of symptoms may be preferred over increased longevity. New less-invasive treatments are likely to improve outcomes in elderly patients who previously have been considered at prohibitive risk for traditional procedures. Clinical trials enrolling elderly patients are limited and recommendations for management from younger patients frequently lack evidence-based support in patients aged >75 years.