Comparison of different cardiac markers in monitoring percutaneous coronary interventions with frequent use of stents and gpIIbIIIa-antagonists

Temporary transcoronary pacing by coated guidewires

Relevant bradycardias during percutaneous coronary intervention (PCI) are a rare event, but they require immediate therapy by temporary pacing. However, transvenous pacing is associated with frequent and severe complications. Therefore, we wanted to evaluate the safety and reliability of trans-coronary pacing by means of a PCI guidewire. Coronary pacing was applied to 70 consecutive patients undergoing PCI. Pacing was performed before and after PCI in a unipolar setting using standard guidewires as a cathode and a skin electrode as an anode. Both were connected to an external pacemaker. Coronary pacing (maximum output at 10 V, impulse duration 2.5 ms) was effective in 60 of 70 patients (85.7%). Successful pacing was achieved in the LAD and diagonal branches in 90% (27 of 30 Pts.), in the LCX and marginal branches 84.2% (16 of 19 Pts.) and in the RCA in 81% (17 of 21 Pts.). Pacing thresholds were comparable in all vessels within a range of 1-10 V averaging 6.6 +/- 2.3 V before and 6.6 +/- 2.2 V after PCI. The impedance ranged from 190-544 Omega with mean pacing impedance for coronary pacing of 424 Omega before and 416 Omega after PCI, respectively. Significant bradycardias during PCI occurred in 7 cases (10%). In three cases (4.3%) temporary coronary pacing became necessary at a maximum pacing duration of 3 min. There were no severe side effects. Coronary spasm occurred in 3 cases (4.3%) after pacing and was promptly reversible after intracoronary application of nitroglycerine. It is concluded that coronary pacing is a safe and feasible method for the treatment of bradycardias during PCI. It avoids additional venous puncture under hemodynamically unstable conditions and subsequent transvenous pacing, which is accompanied by potentially severe complications and additional costs.

Peri-procedural myocardial injury: 2005 update

During the past three decades, percutaneous coronary intervention has become one of the cardinal treatment strategies for stenotic coronary artery disease. Technical advances, including the introduction of new devices such as stents, have expanded the interventional capabilities of balloon angioplasty. At the same time, there has been a decline in the rate of major adverse cardiac events, including Q-wave acute myocardial infarction, emergency coronary artery bypass grafting, and cardiac death. Despite these advances, the incidence of post-procedural cardiac marker elevation has not substantially decreased since the first serial assessment 20 years ago. As of now, these post-procedural cardiac marker elevations are considered to represent peri-procedural myocardial injury (PMI) with worse long-term outcome potential. Recent progress has been made for the identification of two main PMI patterns, one near the intervention site (proximal type, PMI type I) and one in the distal perfusion territory of the treated coronary artery (distal type, PMI type II) as well as for preventive strategies. Integrating these new developments into the wealth of clinical information on this topic, this review aims at giving a current perspective on the entity of PMI.

The relationship between hospital or operator volume and outcomes of coronary patients undergoing percutaneous coronary interventions

The relationship between volume and outcome in medicine has been intensively investigated in the last few decades. The large amount of accumulated data demonstrates that for many surgical or non-surgical procedures and medical conditions, patients being treated in high-volume hospitals or by high-volume physicians have lower mortality rates and better quality of life compared to those treated by low-volume hospitals or by low-volume physicians. Although the degree of the relationship between high volume and better outcome varies, it is persistent across a wide range of procedures and conditions. Percutaneous coronary interventions (PCIs) have an important impact on public health, given the frequency of coronary heart disease for which these procedures are performed. Studies carried out before and after the advent of stents on the relationship between volume and outcome for PCIs have almost consistently reported that performance of PCIs in high-volume institutions or by high-volume operators is associated with improved outcomes for patients, regardless of the specific indication for PCI. For those procedures for which a relationship between high volume and better outcome has been clearly demonstrated, patients as well as their referring physicians should be informed that patients can benefit both in terms of reduced mortality and improved quality of life if they are treated by high-volume health care providers. Consequently, for these procedures, a health care policy aiming at their concentration in high-volume institutions should be strongly considered.

[Urgent or emergent coronary revascularization using bilateral internal thoracic artery after previous clopidogrel antiplatelet therapy]

BACKGROUND

Application of clopidogrel before diagnostic or therapeutical percutaneous coronary interventions has become standard for stent-thrombosis prevention. The irreversible platelet inhibition causes increasing bleeding complications if urgent coronary artery bypass grafting becomes necessary. This study evaluates the effect on bleeding complications of clopidogrel in urgent CABG using bilateral internal thoracic artery (ITA) and saphenous veins in all patients.

METHODS

We retrospectively analyzed 166 patients (operated between 1/00-12/02) with urgent or emergency CABG, using both ITAs and compared 83 patients with previous (within 5 days) clopidogrel and aspirin application to 83 patients without clopidogrel. We evaluated chest tube output, reexploration rate and necessity of blood products, ventilation time and ICU stay.

RESULTS

Both groups were comparable with age, gender, number of performed anastomoses (mean 4/ patient). Chest tube output (24 h) was higher in the clopidogrel group (935 +/- 599 ml vs 754 +/- 335 ml (p = 0.018)), as well as reexploration rate with 7.2% (6 of 83) vs 0% (0 of 83) (p < 0.001). Number of blood products in the clopidogrel group for red cells was 2.41 +/- 1.88 U vs 1.84 +/- 1.47 U p = 0.03, for plateletes 0.43 +/- 0.88 U vs 0.024 +/- 0.22 p = 0.0001, for fresh frozen plasma 0.41 +/- 1.14 U vs 0.096 +/- 0.59 U p = 0.029. Mechanical ventilation time was 11.35 +/- 8.77 h vs 10.57 +/- 9.12 h p = 0.51, ICU stay 32.1 +/- 21.8 h vs. 29.8 +/- 21.1 h (p = 0.48).

CONCLUSIONS

Previous application of clopidogrel in combination with aspirin before urgent CABG induces increased chest tube output, reexploration rate and necessity of blood products, especially of plateletes. Nevertheless, routine use of both ITAs in patients after clopidogrel exposure can be performed with acceptable bleeding complications.