Prevalence and timing of regional myocardial dysfunction after rotational coronary atherectomy

Mechanical Circulatory Support for High-Risk Percutaneous Coronary Intervention

PURPOSE OF REVIEW

This review will focus on the indications of mechanical circulatory support (MCS) for high-risk percutaneous coronary intervention (PCI) and then analyze in detail all MCS devices available to the operator, evaluating their mechanisms of action, pros and cons, contraindications, and clinical data supporting their use.

RECENT FINDINGS

Over the last decade, the interventional cardiology arena has witnessed an increase in the complexity profile of the patients and lesions treated in the catheterization laboratory. Patients with significant comorbidity burden, left ventricular dysfunction, impaired hemodynamics, and/or complex coronary anatomy often cannot tolerate extensive percutaneous revascularization. Therefore, a variety of MCS devices have been developed and adopted for high-risk PCI. Despite the variety of MCS available to date, a detailed characterization of the patient requiring MCS is still lacking. A precise selection of patients who can benefit from MCS support during high-risk PCI and the choice of the most appropriate MCS device in each case are imperative to provide extensive revascularization and improve patient outcomes. Several new devices are being tested in early feasibility studies and randomized clinical trials and the experience gained in this context will allow us to provide precise answers to these questions in the coming years.

Hemodynamic changes in a model of chronic heart failure induced by multiple sequential coronary microembolization in sheep

Although a large variety of animal models for acute ischemia and acute heart failure exist, valuable models for studies on the effect of ventricular assist devices in chronic heart failure are scarce. We established a stable and reproducible animal model of chronic heart failure in sheep and aimed to investigate the hemodynamic changes of this animal model of chronic heart failure in sheep. In five sheep (n = 5, 77 +/- 2 kg), chronic heart failure was induced under fluoroscopic guidance by multiple sequential microembolization through bolus injection of polysterol microspheres (90 microm, n = 25.000) into the left main coronary artery. Coronary microembolization (CME) was repeated up to three times in 2 to 3-week intervals until animals started to develop stable signs of heart failure. During each operation, hemodynamic monitoring was performed through implantation of central venous catheter (central venous pressure [CVP]), arterial pressure line (mean arterial pressure [MAP]), implantation of a right heart catheter {Swan-Ganz catheter (mean pulmonary arterial pressure [PAP mean])}, pulmonary capillary wedge pressure (PCWP), and cardiac output [CO]) as well as pre- and postoperative clinical investigations. All animals were followed for 3 months after first microembolization and then sacrificed for histological examination. All animals developed clinical signs of heart failure as indicated by increased heart rate (HR) at rest (68 +/- 4 bpm [base] to 93 +/- 5 bpm [3 mo][P < 0.05]), increased respiratory rate (RR) at rest (28 +/- 5 [base] to 38 +/- 7 [3 mo][P < 0.05]), and increased body weight 77 +/- 2 kg to 81 +/- 2 kg (P < 0.05) due to pleural effusion, peripheral edema, and ascites. Hemodynamic signs of heart failure were revealed as indicated by increase of HR, RR, CVP, PAP, and PCWP as well as a decrease of CO, stroke volume, and MAP 3 months after the first CME. Multiple sequential intracoronary microembolization can effectively induce myocardial dysfunction with clinical and hemodynamic signs of chronic ischemic cardiomyopathy. The present model may be suitable in experimental work on heart failure and left ventricular assist devices, for example, for studying the impact of mechanical unloading, mechanisms of recovery, and reverse remodeling.

Brain natriuretic peptide increases acutely and much more prominently than atrial natriuretic peptide during coronary angioplasty

BACKGROUND

Increased levels of plasma brain natriuretic peptide (BNP) are observed in patients with congestive heart failure, hypertension, left ventricular hypertrophy, and acute myocardial infarction. However, there are no data on serial changes in plasma levels of BNP in patients undergoing coronary angioplasty.

HYPOTHESIS

The study was undertaken to examine plasma concentrations of BNP together with those of atrial natriuretic peptide (ANP) in patients undergoing percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Plasma concentrations of BNP and ANP were examined in 13 patients with stable angina pectoris and good left ventricular function undergoing PTCA. Blood samples were taken from the femoral vein at baseline, after the first balloon inflation, after the end of the procedure, and 4 h thereafter.

RESULTS

Plasma BNP levels were 14 +/- 4 at baseline, 22 +/- 10 after the first balloon inflation, 28 +/- 12 at the end of the procedure, and 15 +/- 4 pgr/ml 4 h thereafter (F = 13.05, p < 0.00001). Plasma ANP levels were 80 +/- 15, 86 +/- 14, 90 +/- 24, and 75 +/- 6 fmol/l (F = 5.95, p = 0.002), respectively. The increase of BNP at the end of the procedure was related to the increase of ANP (r = 0.78, p = 0.002).

CONCLUSION

Plasma BNP levels increase acutely and much more prominently than those of plasma ANP during coronary angioplasty; however, plasma BNP levels return to baseline values shortly after the end of the procedure.

Coronary microembolization

Atherosclerotic plaque rupture is the key event in the pathogenesis of acute coronary syndromes and it also occurs during coronary interventions. Atherosclerotic plaque rupture does not always result in complete thrombotic occlusion of the epicardial coronary artery with subsequent impending myocardial infarction, but may in milder forms result in the embolization of atherosclerotic and thrombotic debris into the coronary microcirculation. This review summarizes the present experimental pathophysiology of coronary microembolization in animal models of acute coronary syndromes and highlights the main consequences of coronary microembolization--reduced coronary reserve, microinfarction, inflammation and oxidative modification of contractile proteins, contractile dysfunction and perfusion-contraction mismatch.Furthermore, the review presents the available clinical evidence for coronary microembolization in patients and compares the clinical observations with observations in the experimental model.

Preprocedural statin use is associated with a reduced hazard of postprocedural myonecrosis in patients undergoing rotational atherectomy--a propensity-adjusted analysis

Incidence of myonecrosis in patients undergoing rotational atherectomy was evaluated by preprocedural statin use. The incidence of any myonecrosis (24.1% vs 52.3%, P < .001) or significant myonecrosis (7.5% vs 21.8%, P < .001) was significantly lower among patients pretreated with statins. This difference remained significant after multivariable and propensity adjustment.

Increase in serum troponin-I following rotational atherectomy reliably predicts the occurrence of reversible wall motion abnormalities

BACKGROUND

There is growing evidence that microdebris pulverized by rotational atherectomy (RA) may have a deleterious effect on coronary microcirculation and ventricular contraction. However, the incidence and the predictors of worsening of left ventricular wall motion following RA are unknown.

METHODS

Thirty patients without a known previous anterior wall myocardial infarction who underwent RA-facilitated angioplasty for de novo lesions of left anterior descending coronary artery were evaluated. Global and anterior wall regional left ventricular ejection fraction (LVEF and AREF) were analyzed before and after RA. Serum troponin-I, CK, and CK-MB concentrations were assayed.

RESULTS

Target lesion length was greater (P=0.03), post-procedural minimal lumen diameter was smaller (P<0.01), and serum troponin-I immediately after RA was higher (P=0.01) in 16 patients with a decrease in the AREF of at least 15% than in those without. Stepwise logistic regression analysis identified one independent predictor of such worsening of AREF, troponin-I> or =0.1 ng/ml immediately after the procedure (P<0.01), with sensitivity of 81%, specificity of 79%, and relative risk of 3.8.

CONCLUSIONS

Our results suggest that RA can cause substantial deterioration in left ventricular wall motion. Serum troponin-I, a sensitive indicator of myocardial damage, may be useful in predicting reversible LV wall motion abnormalities following RA.

Coronary microembolization

Atherosclerotic plaque rupture is a key event in the pathogenesis of acute coronary syndromes and during coronary interventions. However, it does not always result in complete thrombotic occlusion of the entire epicardial coronary artery with subsequent acute myocardial infarction; in milder forms the result can be embolization of atherosclerotic and thrombotic debris into the coronary microcirculation. This review summarizes the available morphological evidence for coronary microembolization in patients who died from coronary artery disease, most notably from sudden death, and then goes on to address the experimental pathophysiology of coronary microembolization in animal models of acute coronary syndromes and heart failure. Finally, the review presents the available clinical evidence for coronary microembolization in patients, highlights its key features (ie, arrhythmias, contractile dysfunction, infarctlets and reduced coronary reserve) and addresses its prevention by mechanical protection devices and glycoprotein IIb/IIIa antagonism.

Left ventricular electromechanical mapping: preliminary evidence of electromechanical changes after successful coronary intervention

BACKGROUND

Postinterventional ischemic myocardial dysfunction and its sequelae are still not well understood.

METHODS AND RESULTS

To gain further insight into the immediate physiologic consequences of coronary interventions and to better understand the nature of changes that result from such interventions, we analyzed 96 electromechanical maps from 48 patients before and after successful, uncomplicated percutaneous coronary interventions (PCI). A NOGA system was used to construct the map of the endocardial surface. Reproducibility was confirmed by constructing 10 additional maps in 5 patients who did not undergo an intervening procedure. Discordant areas were defined as those with preserved unipolar voltage (> or =7.5 mV) and diminished linear local shortening (< or =12.5%). On the basis of comparison of the variations in the discordance values (%) in the reproducibility group, patients were considered improved (lower values), worsened (higher values), or unchanged. In the reproducibility group, the mean variation in discordance was 2.18% +/- 1.26%, whereas in the PCI group, it was 21.97% +/- 18.47%. In the PCI group (rotational atherectomy subgroup [n = 10] and stent subgroup [n = 38]), left ventricular discordance values improved in 19 patients (39.6%), worsened in 24 (50%), and remained the same in 5 (10.4%). Of all variables analyzed, only abciximab was significantly associated with postintervention improvement in discordance (P =.02; odds ratio 0.165, 95% CI 0.03-0.88), regardless of the type of intervention performed (P =.61), whereas heparin alone was associated with more discordance after intervention (odds ratio 6.07, 95% CI 1.14-32.40).

CONCLUSIONS

We assessed the effect of percutaneous revascularization on myocardium by use of electromechanical data. For the first time, changes in linear local shortening in areas of preserved unipolar voltage were quantified, and worsening after successful Thrombolysis In Myocardial Infarction grade III coronary interventions was registered. The only variable associated with improvement on electromechanical data after interventions was the use of abciximab. This raises the question of the possible potential of this new diagnostic tool in assessing and quantifying postinterventional microvasculature pathological changes.

Coronary microembolization

Atherosclerotic plaque rupture is a key event in the pathogenesis of acute coronary syndromes and during coronary interventions. Atherosclerotic plaque rupture does not always result in complete thrombotic occlusion of the entire epicardial coronary artery with subsequent acute myocardial infarction; however, in milder forms it may result in the embolization of atherosclerotic and thrombotic debris into the coronary microcirculation. The present report summarizes the available morphologic evidence for coronary microembolization in patients who died of coronary artery disease, especially sudden death. The report then goes on to address the experimental pathophysiology of coronary microembolization in animal models of acute coronary syndromes and heart failure. Finally, the report presents the available clinical evidence for coronary microembolization, highlights its key features--arrhythmias, contractile dysfunction, infarctlets and reduced coronary reserve--and addresses prevention by mechanical protection devices and glycoprotein IIb/IIIa antagonism.

[In-hospital major complications associated with rotational atherectomy: experience with 800 patients at a single center]

INTRODUCTION

Rotational atherectomy is usually performed in patients with angiographically determined high risk coronary lesions. The aim of this study was to evaluate the rate of major adverse cardiac events (death, Q-wave infarction or new revascularization) after rotational atherectomy, as well as to identify the clinical characteristics associated with this incidence.

PATIENTS AND METHODS

The study population included 800 patients treated with rotational atherectomy from 1993 to 1999: 512 (64%), for de novo lesions, and 288 (36%) for restenosis. Balloon dilation and coronary stenting was performed in 95% and 34% of patients, respectively.

RESULTS

During hospitalization, 17 patients (2.1%) died, 16 (2%) had a Q-wave infarction, 30 (3.8%) a non-Q infarction, and new revascularization was performed in 28 (3.5%). The incidence of major adverse cardiac events was 6.5% (n = 52), this incidence being higher in the presence of diabetes (8.9 vs. 4.4%; p = 0.01), unstable angina or acute/recent myocardial infarction (7.6 vs. 3.3%; p = 0.02), multivessel disease (8.6 vs. 3.3%; p < 0.01), treated vessel other than right coronary (7.0 vs. 1.7%; p = 0.01), procedure in > 1 vessel (10.7 vs. 4.7%; p < 0.01), angiographic failure (62.5 vs. 5.5%; p < 0.001), and de novo lesions (8.4 vs. 2.5%; p < 0.01), with diabetes and treatment of de novo lesions being independent predictors of major adverse cardiac events. However, age, previous infarction, and left ventricular dysfunction, were not associated with the rate of events.

CONCLUSION

Some simple variables are associated with a higher incidence of major adverse cardiac events after rotational atherectomy. Advanced age, previous infarction and left ventricular dysfunction, however, do not necessarily imply a poorer prognosis in these patients.

Influence of a platelet GPIIb/IIIa receptor antagonist on myocardial hypoperfusion during rotational atherectomy as assessed by myocardial Tc-99m sestamibi scintigraphy

OBJECTIVES

This study evaluated the effect of the glycoprotein IIb/IIIa (GPIIb/IIIa) antagonist abciximab on myocardial hypoperfusion during percutaneous transluminal rotational atherectomy (PTRA).

BACKGROUND

PTRA may cause transient ischemia and periprocedural myocardial injury. A platelet-dependent risk of non-Q-wave infarctions after directional atherectomy has been described. The role of platelets for the incidence and severity of myocardial hypoperfusion during PTRA is unknown.

METHODS

Seventy-five consecutive patients with complex lesions were studied using resting Tc-99m sestamibi single-photon emission computed tomography prior to PTRA, during, and 2 days after the procedure. The last 30 patients received periprocedural abciximab (group A) and their results were compared to the remaining 45 patients (group B). For semiquantitative analysis, myocardial perfusion in 24 left ventricular regions was expressed as percentage of maximal sestamibi uptake.

RESULTS

Baseline characteristics did not differ between the groups. Transient perfusion defects were observed in 39/45 (87%) patients of group B, but only in 10/30 (33%) patients of group A (p < 0.001). Perfusion was significantly reduced during PTRA in 3.3 +/- 2.5 regions in group B compared to 1.4 +/- 2.5 regions in group A (p < 0.01). Perfusion in the region with maximal reduction during PTRA in groups B and A was 76 +/- 15% and 76 +/- 15% at baseline, decreased to 56 +/- 16% (p < 0.001) and 67 +/- 14%, respectively, during PTRA (p < 0.01 A vs. B), and returned to 76 +/- 15% and 80 +/- 13%, respectively, after PTRA. Nine patients in group B (20%) and two patients in group A (7%) had mild creatine kinase and/or troponin t elevations (p = 0.18). Patients with elevated enzymes had larger perfusion defects than did patients without myocardial injury (4.2 +/- 2.7 vs. 2.3 +/- 2.5 regions, p < 0.05).

CONCLUSIONS

These data indicate that GPIIb/IIIa blockade reduces incidence, extent and severity of transient hypoperfusion during PTRA. Thus, platelet aggregation may play an important role for PTRA-induced hypoperfusion.