Biomedical subjects

Antonio G Rebuzzi

Publications and source records attributed to Antonio G Rebuzzi.

12 recordsLinked to original sources

PubMed2006

Reversible microvascular dysfunction coupled with persistent myocardial dysfunction: implications for post-infarct left ventricular remodelling.

BACKGROUND: Recent studies have shown that microvascular dysfunction after myocardial infarction is a dynamic phenomenon. AIMS: To evaluate the implications of dynamic changes in microvascular dysfunction on contractile recovery and left ventricular remodelling, and to identify the ideal timing of assessment of such microvascular dysfunction. METHODS AND RESULTS: In 39 patients with a first myocardial infarction who underwent successful percutaneous coronary intervention, microvascular dysfunction was studied by myocardial contrast echocardiography (MCE) at 24 h, 1 week and 3 months after the procedure. Real-time MCE was performed by contrast pulse sequencing and intravenous Sonovue. 14 patients exhibited left ventricular remodelling at 3 months (>20% increase in left ventricular end-diastolic volume, group B), whereas 25 did not (group A). Microvascular dysfunction was similar in the two groups at 24 h and improved in group A only, being significantly better than that of group B at 1 week (p<0.05) and 3 months (p<0.005). Improvement in microvascular dysfunction was not associated with improvement in wall motion in the same segments. With multivariate analysis including all echocardiographic variables, microvascular dysfunction at 1 week was found to be the only independent predictor of left ventricular remodelling (p<0.01). With a cut-off value of 1.4, 1-week microvascular dysfunction predicts left ventricular remodelling with sensitivity and specificity of 73%. CONCLUSIONS: Improvement in microvascular dysfunction occurs early after myocardial infarction, although it is not associated with a parallel improvement in wall motion but is beneficial in preventing left ventricular remodelling. Accordingly, 1-week microvascular dysfunction is a powerful and independent predictor of left ventricular remodelling.

Contrast Media↗

PubMed2006

Thrombus aspiration reduces microvascular obstruction after primary coronary intervention: a myocardial contrast echocardiography substudy of the REMEDIA Trial.

OBJECTIVES: The aim of this study was to clarify the role of microembolization in the genesis of microvascular obstruction (MO) after percutaneous coronary intervention (PCI). BACKGROUND: Fifty consecutive patients entered the myocardial contrast echocardiography (MCE) substudy of the REMEDIA (Randomized Evaluation of the Effect of Mechanical Reduction of Distal Embolization by Thrombus Aspiration in Primary and Rescue Angioplasty) trial, which defined the role of a new thrombus-aspirating device in preventing distal microembolization after PCI. METHODS: A total of 25 patients were randomized to be pretreated with thrombus aspiration before PCI of the culprit lesion and 25 received standard PCI. At 24 h, 1 week, and 6 months after PCI, MCE was performed by Sonovue, and real-time imaging was performed by contrast pulse sequencing technology. Regional wall motion score index (WMSI), contrast score index (CSI), endocardial length of wall motion abnormality (WML) and contrast defect (CDL), end-diastolic and end-systolic left ventricular (LV) volumes, and ejection fraction were calculated. RESULTS: At each time point, in patients treated with a thrombus-aspiration filter device, WMSI, CSI, WML, and CDL were significantly lower and ejection fraction higher (p < 0.05 vs. control patients), whereas LV volumes were slightly but not significantly smaller compared with control patients. In the overall study population, the extent of MO significantly correlated with temporal changes in LV volumes. CONCLUSIONS: Thrombus aspiration used at the time of PCI significantly reduces the extent of MO and myocardial dysfunction, although it does not have a significant favorable effect in preventing LV remodeling. Thus, the beneficial effect of thrombus aspiration occurs at the microvascular level, but additional mechanisms may play a role in influencing the final extent of MO, which strictly correlates with post-infarct LV remodeling.

Aged↗

PubMed2006

Baseline systemic inflammatory status and no-reflow phenomenon after percutaneous coronary angioplasty for acute myocardial infarction.

BACKGROUND: Systemic inflammation is involved in several pathological cardiovascular processes. However, whether it plays a role in the no-reflow phenomenon occurring in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI) is unknown. METHODS: We studies 60 consecutive patients (59.5+/-12 years, 82% males) with a first ST-segment elevation AMI, treated by primary or rescue PCI within 6 h of symptom onset. Angiographic indexes of no-reflow, evaluated at the end of the procedure, included coronary TIMI flow grading, corrected TIMI frame count (c-TFC) and myocardial blush grade (MBG). ECG indexes of no-reflow included the lack of ST segment resolution (defined as a reduction <50% of the measured ST-segment elevation at 90 min, compared to the admission ECG), as analyzed both in the single lead with the maximal ST elevation and in all leads showing ST elevation on admission. Patients were divided into two groups according to baseline high-sensitivity C-reactive protein (CRP) serum levels measured on admission: high CRP group (CRP>5 mg/L) and low CRP group (CRP<5 mg/L). RESULTS: A similar prevalence of final TIMI flow<3 and MBG<3 was observed in patients with high and low CRP serum levels (30% vs. 12%, p=0.1, and 50% vs. 53%, p=1.0, respectively), and c-TFC was also similar in the two groups (26+/-4.5 vs. 24+/-6, p=0.5). Accordingly, the prevalence of lack of ST-segment resolution in the two groups was similar, both by the single-lead method (25% vs. 25%, p=1.0) and the multiple-lead method (29% vs. 19%, p=0.4). CONCLUSION: In this study we failed to demonstrate any significant association between CRP serum levels on admission and coronary no-reflow, as assessed by both angiographic and ECG parameters in AMI patients treated by successful primary or rescue PCI within 6 h of chest pain onset.

Angioplasty, Balloon, Coronary↗

PubMed2006

Endothelin-1 and acute myocardial infarction: a no-reflow mediator after successful percutaneous myocardial revascularization.

AIMS: No-reflow after a primary percutaneous coronary intervention (PCI) is associated with a high incidence of left ventricular (LV) failure and a poor prognosis. Endothelin-1 (ET-1) is a potent endothelium-derived vasoconstrictor peptide and an important modulator of neutrophil function. Elevated systemic ET-1 levels have recently been reported to predict a poor prognosis in patients with acute myocardial infarction (AMI) treated by primary PCI. We aimed to investigate the relationship between systemic ET-1 plasma levels and no-reflow in a group of AMI patients treated by primary PCI. METHODS AND RESULTS: A group of 51 patients (age 59+/-9.9 years, 44 males) with a first AMI, undergoing successful primary or rescue PCI, were included in the study. Angiographic no-reflow was defined as coronary TIMI flow grade < or =2 or TIMI flow 3 with a final myocardial blush grade < or =2. Blood samples were obtained from all patients on admission for ET-1 levels measurement. No reflow was observed in 31 patients (61%). Variables associated with no-reflow at univariate analysis included culprit lesion of the left anterior coronary descending artery (LAD) (67 vs. 29%, P=0.006) and ET-1 plasma levels (3.95+/-0.7 vs. 3.3+/-0.8 pg/mL, P=0.004). At multivariable logistic regression analysis, ET-1 was the only significant predictor of no-reflow (P=0.03) together with LAD as the culprit vessel (P=0.04). CONCLUSION: ET-1 plasma levels predict angiographic no-reflow after successful primary or rescue PCI. These findings suggest that ET-1 antagonists might be beneficial in the management of no-reflow.

Angioplasty, Balloon, Coronary↗

PubMed2006

A case of fatal stent thrombosis after Carbostent implantation: is clopidogrel alone antiplatelet therapy a safe alternative to aspirin alone antiplatelet therapy?

We describe a case of fatal stent thrombosis after Carbostent implantation and clopidogrel alone antiplatelet therapy in a patient affected by rectal cancer who does not tolerate aspirin. He had three-vessel disease, with occlusion of the right and left anterior descending coronary artery and a severe stenosis of the proximal left circumflex. High-risk circumflex percutaneous coronary intervention (PCI) was performed under left ventricular assistance by Impella device with an optimal final angiographic result. After 2 h, however, the patient developed chest pain with marked ST segment elevation in the infero-lateral leads, due to stent thrombosis, and hypotention which rapidly degenerated into cardiac arrest, electromechanical dissociation and death. At the present time the choice between PCI at high risk of stent thrombosis followed by low risk cancer resection and cancer resection at high risk of peri-operative myocardial infarction followed by low risk PCI remains difficult.

Aged↗

PubMed2006

Relation of heart rate variability to serum levels of C-reactive protein in patients with unstable angina pectoris.

Heart rate variability (HRV) and systemic markers of inflammation have prognostic value in patients with unstable angina pectoris (UAP). However, it is unknown whether any relation exists between HRV parameters and indexes of inflammation in this clinical context. We assessed HRV on 24-hour electrocardiographic Holter recordings, performed within 24 hours of admission, and measured C-reactive protein (CRP) serum levels by a high-sensitivity assay on admission, in 531 patients with UAP (65+/-10 years of age; 347 men) who were enrolled in the prospective multicenter study Stratificazione Prognostica dell'Angina Instabile (SPAI). A significant inverse correlation was found between CRP levels and all HRV parameters, with the highest r coefficient shown with SD of all RR intervals (r= -0.23; p<0.001) in the time domain and with very low-frequency amplitude (r= -0.22; p<0.001) in the frequency domain. When patients were categorized into 4 groups according to CRP quartile levels, statistically significant lower HRV values were observed in the upper CRP quartile. On separate multiple regression analyses, including the most important clinical and laboratory variables, SD of all RR intervals and very low-frequency amplitude were the most significant predictors of increasing CRP levels (p<0.001 for the 2 comparisons). In contrast, in models with SD of all RR intervals and very low-frequency amplitude as dependent variables, CRP was a strong predictor of impaired cardiac autonomic function (p<0.001 for the 2 comparisons). Thus, our data show that, in patients with UAP, high levels of serum CRP levels are significantly associated with decreased HRV, suggesting a possible pathophysiologic link between cardiac autonomic dysfunction and inflammatory activity.

Adult↗

PubMed2005

Angiographic evaluation of the effect of intracoronary abciximab administration in patients undergoing urgent PCI.

BACKGROUND: Recent data suggest that the intracoronary (i.c.) administration of a systemic bolus dose of abciximab during PCI may increase the efficacy of this antiplatelet drug. However, the effect of i.c. abciximab on coronary angiographic flow has been not clarified. METHODS: We studied 37 consecutive patients with acute coronary syndromes (ACS) who underwent successful urgent PCI on the target vessel and were treated by an i.c. abciximab bolus (0.25 mg/kg) prior to the first balloon inflation (Group IC), and 37 matched controls who were treated by intravenous (i.v.) abciximab bolus at the same dose (Group IV). Corrected TIMI frame count (CTFC) in the culprit and in a non-culprit coronary artery branch was assessed before treatment, immediately after intracoronary administration of abciximab bolus and at the end of the procedure. RESULTS: After administration of abciximab, CTFC significantly decreased from 48+37 to 33+30 (P=0.001) in the culprit vessel while in the non-culprit vessel it remained unchanged (16+7 pre-treatment and 16+7 post-treatment, P=0.68). Final CTFC was 12+4 in Group IC and 14+5 in Group IV (P=0.069). Post-treatment mean peak of the cardiac enzymes showed a trend toward reduction in Group IC compared with Group IV. CONCLUSIONS: The i.c. administration of abciximab bolus acutely decreases CTFC through culprit vessels of patients with ACS undergoing urgent PCI. Further studies evaluating the potential clinical benefits associated with i.c. abciximab administration are warranted.

Abciximab↗

PubMed2005

Directional atherectomy before stenting versus stenting alone in percutaneous coronary interventions: a meta-analysis.

Plaque debulking before stenting is still controversial. We performed a meta-analysis of 12 randomized and non-randomized trials comparing directional coronary atherectomy (DCA) before stenting versus stenting alone. Angiographic end points were acute gain, late loss and angiographic restenosis rate. Clinical end points were early major adverse cardiac events [MACEs: death, Q-wave myocardial infarction (MI), non-Q-wave MI], late MACEs (death, Q-wave MI) and target lesion revascularization (TLR). Data are expressed as odds ratio (OR) with 95% confidence intervals (CI) or weighted mean difference (WMD) with 95% CI, as appropriate. A total of 1216 patients undergoing DCA before stent and 1484 patients undergoing stent alone have been included. DCA before stent was associated to a better acute gain compared to stenting alone (WMD 0.23, [0.18-0.28]; p<0.0001), to a striking reduction of angiographic restenosis rate (OR of 0.67, [0.54-0.84], p=0.0003) and to a significantly lower rate of late TLR (OR 0.73 [0.59-0.91], p=0.006). Late loss did not differ between the two groups (WMD 0.00 [-0.08 and 0.08], p=0.98). We found a higher rate of early MACEs for the combined approach (OR 1.87 [1.16-3.02], p=0.01), with similar prevalence of late MACEs (OR 0.83 [0.65-1.06], p=0.13). In conclusion, this meta-analysis demonstrates that DCA before stenting is superior to stenting alone with regard to acute angiographic results and TLR with a similar prevalence of late MACEs. The higher prevalence of early MACEs with DCA before stenting, however, is disturbing and probably related to distal embolization.

Aged↗

PubMed2005

Coronary vasospasm secondary to hypercholinergic crisis: an iatrogenic cause of acute myocardial infarction in myasthenia gravis.

Patients with myasthenia gravis undergo lifelong treatment with anticholinesterase agents. While the heart is usually unaffected by this disease, clinicians should bear in mind the potential adverse interaction between cardiac function and the underlying myasthenic disease or its specific medications. In the present article we report, to the best of our knowledge for the first time in the literature, a case of vasospastic acute myocardial infarction due to iatrogenic hypercholinergic crisis secondary to anticholinesterase therapy in an elderly female with myasthenia gravis. This clinical vignette emphasizes the importance of taking into account the potential vasospastic effect of anticholinesterase drugs. Indeed, prompt recognition of the pathophysiology of myocardial ischemia due to iatrogenic hypercholinergic crisis is pivotal to the timely and appropriate management of this medical emergency, as well as prevention of future recurrences.

Aged↗

PubMed2005

Endogenous G-CSF and CD34+ cell mobilization after acute myocardial infarction.

BACKGROUND: Several reports showed an increase of CD34(+) stem/progenitor cell count early after an acute myocardial infarction (AMI), suggesting a contribution of bone marrow cells in myocardial regeneration after the acute event. Nevertheless, at present plasma mediators of CD34(+) cell mobilization from bone marrow to peripheral blood in patients with AMI are poorly understood. Aim of our study was to establish the impact of different well-known mobilizing cytokines on spontaneous stem cell mobilization in patients with different ischemic heart syndromes, such as the AMI and the chronic stable angina (CSA), compared to healthy controls. METHODS: In 16 patients with AMI, 18 with CSA and 22 healthy blood donors the concentration of CD34(+) cells, and mobilizing cyokines (G-CSF, SCF, VEGF, SDF1-alpha) were assessed. RESULTS: The peak number of circulating CD34(+) cells in AMI patients (8.58+/-2.08 cells/microl) was higher than that observed in patients with CSA (3.41+/-0.56 cells/microl, p=0.0061) or in healthy controls (2.18+/-0.35 cells/microl, p<0.001). However endogenous G-CSF was significantly higher in the serum of patients with AMI compared to CSA patients and to controls and in CSA patients compared to controls. Interestingly, as regards VEGF, while this cytokine was increased in AMI with respect to control and CSA group, the latter showed a significantly lower concentration with respect to controls. Finally SDF-1 alpha was higher in AMI patients with respect to controls. CD34(+) cells were significantly correlated to G-CSF (directly) and to SCF (inversely) in patients with AMI. CONCLUSION: In the present study, we have demonstrated for the first time that the spontaneous mobilization of CD34(+) cells into the peripheral blood of patients with AMI is significantly correlated to endogenous G-CSF. Considering recent data suggesting a potential favourable effect of circulating CD34(+) cells on left ventricular function, the present evidence of a correlation between endogenous G-CSF and CD34(+) cell levels supports the pharmacological administration of G-CSF as a non-invasive option for regeneration of myocardial tissue after AMI.

Aged↗

PubMed2005

Rescue percutaneous coronary intervention for failed thrombolysis in a patient with anomalous coronary arteries.

Coronary artery anomalies (CAA) often render technically difficult the completion of coronary angiography and intervention. Their presence in patients undergoing emergency angiography for acute myocardial infarction (AMI) is particularly challenging for interventional cardiologists. In this article, we report, for the first time in the literature, a case of rescue percutaneous coronary intervention for failed thrombolysis in a patient with AMI due to occlusion of a left circumflex coronary artery with anomalous origin from right sinus of Valsalva (in an anomalous left coronary system also including an anomalous origin of the left anterior descending artery from the right sinus). In particular, the present clinical vignette emphasizes the importance of a thorough search for the culprit vessel during cardiac catheterization. Especially in the emergency setting, non-invasive methods of ischemia localization, such as ST-segment elevation at the ECG and wall motion abnormalities at echocardiography, are of pivotal usefulness to guide the interventional cardiologist in identifying and treating the diseased coronary vessel in a timely and effective fashion.

Angioplasty, Balloon, Coronary↗

PubMed2005

Mobilization of bone marrow-derived stem cells after myocardial infarction and left ventricular function.

AIMS: Recent data suggest that the administration of bone marrow-derived stem cells (BMSC) might improve myocardial perfusion and left ventricular (LV) function after acute myocardial infarction (AMI). The aim of this study was to assess spontaneous mobilization of BMSC expressing the haematopoietic and endothelial progenitor cell-associated antigen CD34+ after AMI and its relation to post-infarction remodelling. METHODS AND RESULTS: Peripheral blood concentration of CD34+ BMSC was measured by flow cytometry in 54 patients with AMI, 26 patients with chronic stable angina (CSA), and 43 normal healthy subjects. In patients with AMI, LV function was measured by 2D-echocardiography. Eighteen AMI patients were reassessed at 1 year. BMSC concentration was higher in patients with AMI (mean peak value: 7.04+/-6.27 cells/microL), than in patients with CSA (3.80+/-2.12 cells/microL, P=0.036) and in healthy controls (1.87+/-1.52 cells/microL, P<0.001). At multivariable analysis statin use (P<0.001), primary percutaneous intervention (P=0.048) and anterior AMI (P=0.05) were the only independent predictors of increased BMSC mobilization after AMI. In the 28 patients without subsequent acute coronary events reassessed at 1 year follow-up, CD34+ cell concentration was an independent predictor of global and regional improvement of LV function (r=0.52, P=0.004 and r=-0.41, P=0.03, respectively). CONCLUSION: AMI is followed by enhanced spontaneous mobilization of BMSC, in particular, in patients on statin therapy and following a primary percutaneous intervention. More importantly persistent spontaneous mobilization of BMSC might contribute to determine a more favourable post-AMI remodelling.

Antigens, CD34↗