Attilio Renzulli

Diagnosis of Acute Aortic Dissection by D-Dimer. The International Registry of Acute Aortic Dissection Substudy on Biomarkers (IRAD-Bio) Experience

Background— D-dimer has been reported to be elevated in acute aortic dissection. Potential use as a “rule-out” marker has been suggested, but concerns remain given that it is elevated in other acute chest diseases, including pulmonary embolism and ischemic heart disease. We evaluated the diagnostic performance of D-dimer testing in a study population of patients with suspected aortic dissection. Methods and Results— In this prospective multicenter study, 220 patients with initial suspicion of having acute aortic dissection were enrolled, of whom 87 were diagnosed with acute aortic dissection and 133 with other final diagnoses, including myocardial infarction, angina, pulmonary embolism, and other uncertain diagnoses. D-dimer was markedly elevated in patients with acute aortic dissection. Analysis according to control disease, type of dissection, and time course showed that the widely used cutoff level of 500 ng/mL for ruling out pulmonary embolism also can reliably rule out aortic dissection, with a negative likelihood ratio of 0.07 throughout the first 24 hours. Conclusion— D-dimer levels may be useful in risk stratifying patients with suspected aortic dissection to rule out aortic dissection if used within the first 24 hours after symptom onset.

Acute Kidney Injury: A Relevant Complication After Cardiac Surgery

Acute kidney injury (AKI) occurs in as many as 40% of patients after cardiac surgery and requires dialysis in 1% of cases. Acute kidney injury is associated with an increased risk of mortality and morbidity, predisposes patients to a longer hospitalization, requires additional treatments, and increases the hospital costs. Acute kidney injury is characterized by a progressive worsening course, being the consequence of an interplay of different pathophysiologic mechanisms, with patient-related factors and cardiopulmonary bypass as major causes. Recently, several novel biomarkers have emerged, showing reasonable sensitivity and specificity for AKI prediction and protection. The development and implementation of potentially protective therapies for AKI remains essential, especially for the relevant impact of AKI on early and late survival.

Risk factors for pacemaker implantation following aortic valve replacement: a single centre experience

Objective: To identify perioperative clinical predictors of permanent pacemaker implantation following aortic valve replacement. Design and patients: Prospective cohort study on 276 patients submitted for aortic valve replacement: 267 patients (mean (SD) age, 57.5 (14) years) with no conduction disturbances, and nine patients (67.7 (5) years) with severe conduction disturbances requiring permanent pacing; 65 perioperative variables (38 preoperative, eight intraoperative, and 19 postoperative) were considered. Results: Nine patients (3.2%) had irreversible second or third degree atrioventricular (AV) block requiring permanent pacing. Risk factors for permanent pacing identified by univariate analysis were: preoperative: additional valvar disease, aortic regurgitation, myocardial infarction, pulmonary hypertension, anaemia, use of digitalis; intraoperative: cardiac arrest; postoperative: cardiac arrest, conduction disturbances, electrolytic imbalance, angiotensin converting enzyme inhibitor use. Multivariate logistic regression analysis identified preoperative aortic regurgitation (p < 0.005; odds ratio (OR) 6.6, 95% confidence interval (CI) 1.6 to 12.2), myocardial infarction (p < 0.0005; OR 15.2, 95% CI 6.3 to 19.9), pulmonary hypertension (p < 0.005; OR 12.5, 95% CI 3.2 to 18.3), and postoperative electrolyte imbalance (p < 0.01; OR 4.5, 95% CI 1.3 to 6.4). Conclusions: Irreversible AV block requiring permanent pacemaker implantation is an uncommon condition following aortic valve replacement. Previous aortic regurgitation, myocardial infarction, pulmonary hypertension, and postoperative electrolyte imbalance should be considered in order to identify patients at increased risk for advanced AV block.

Variables predicting adverse outcome in patients with deep sternal wound infection

BACKGROUND Mortality after deep sternal wound infection (DSWI) ranges between 5% and 47%. Variables predicting hospital mortality and prolonged hospital stay are still to be assessed. METHODS Among 13,420 patients who underwent cardiac surgery in our institution between 1979 and 1999, DSWI developed in 112 cases (0.8%). Multiple variables were recorded prospectively and analyzed retrospectively as predictors of hospital death and prolonged (>30 days) hospital stay. The analyzed variables were divided into three groups: (1) related to the patient, including demographic variables and preoperative conditions; (2) related to cardiac operation; and (3) related to infection. Predictive variables were assessed by univariate and multivariate logistic regression analysis. RESULTS Hospital mortality was 16.9%. The hospital stay of the 93 discharged patients ranged between 16 and 180 days (mean 31.3 +/- 15.2). Length of cardiac operation, length of stay in intensive care unit, interval between symptoms of DSWI and wound debridement were found to be the most significant predictors of bad outcome following DSWI. CONCLUSIONS In our study demographic variables and preoperative conditions did not affect the prognosis of DSWI. Lower mortality rate and shorter hospital stay could be achieved with earlier and aggressive treatment of DSWI.

Prosthetic valve obstruction: thrombolysis versus operation.

An acute obstruction is a life-threatening complication of mechanical valve prostheses, and is caused by the formation of fresh clot or fibrous tissue overgrowth, or both. Accurate selection of the most appropriate treatment for a particular patient is mandatory. From January 1991 to July 1992, 28 cases of prosthetic thrombosis were managed. Twenty patients underwent surgical treatment, with one operative death, and 8 patients were treated with thrombolysis using recombinant tissue-type plasminogen activator (rt-PA). The criteria for using thrombolysis were (1) the recent onset of symptoms, (2) transesophageal echocardiographic evidence of clots on the valve or cardiac chambers, and (3) preserved disc excursions. All patients who underwent thrombolysis had mechanical valves (two bileaflets, four tilting discs, and two ball valves); seven valves were in the mitral position and one was in the aortic. Symptoms of obstruction consisted of cardiac failure in 6 cases or thromboembolism in 5, or both. The mean interval between the onset of symptoms and the initiation of thrombolysis was 81 +/- 65 hours. After infusion of the rt-PA, normal valve function was restored in all patients, as documented by transesophageal echocardiography. No deaths or neurologic complications occurred; there was one episode of minor peripheral embolism. Thrombolysis using rt-PA may be the appropriate treatment in patients with primary thrombosis of mechanical valves, thereby avoiding the operation-related risks.

Obstruction of Mechanical Mitral Prostheses: Analysis of Pathologic Findings

BACKGROUND The pathologic and echocardiographic findings observed in 87 patients with mitral valve obstruction were reviewed to ascertain the incidence of pannus formation versus that of thrombosis, the relationship between the two, and the time to the occurrence of pannus versus the time to thrombosis. METHODS Pannus morphology (concentric or eccentric), its location on the valve (atrial, ventricular, atrioventricular), and the presence and relationship of associated thrombi (atrial, ventricular, atrioventricular) were analyzed. The times between valve replacement and the occurrence of obstruction were also compared. RESULTS There were 10 caged-ball valves, 65 tilting-disc valves, and 12 bileaflet valves. Seventy-two patients underwent prosthetic replacement, and 15 underwent thrombolysis. Pannus alone was found in 27, pannus and thrombus in 39, and thrombus alone in 21. Primary thrombosis occurred earlier than pannus formation (p = 0.04); this was true for patients with bileaflet valves (p = 0.006) and those with tilting-disc valves (p = 0.04). Pannus was atrial in 19.7% (13/66), ventricular in 21.2% (14/66), and atrioventricular in 59.1% (39/66). Pannus morphology was concentric in 22.7% (15/66) and eccentric in 77.3% (51/66). Atrial secondary thrombi occur more often in patients with atrioventricular pannus (p = 0.04). Eight patients had reobstruction; this was caused by pannus formation in 5 and by thrombosis in 3. Five underwent reoperation, and 3 underwent thrombolysis. Reobstruction occurred earlier than the first event. CONCLUSIONS The frequency of pannus formation is much higher than that of thrombus formation, but thrombosis is of earlier onset than pannus formation. Thrombosis is due to the deposition of clots on the prosthesis, and a pannus occurs as the result of an inflammatory reaction developing on both valve surfaces.

Recurrent infective endocarditis: a multivariate analysis of 21 years of experience

BACKGROUND To evaluate which variables predict recurrence of endocarditis after surgical treatment, we reviewed our 21-year experience. METHODS Between January 1979 and May 2000, 308 consecutive valve replacement procedures for infective endocarditis were performed in 271 patients. Univariate and multivariate time-related analyses were performed to retrospectively evaluate the role of the following variables in the development of recurrent postoperative endocarditis: gender, site of endocarditis, previous valve disease, drug abuse, diabetes, positive valve/blood cultures, sepsis, perivalvular involvement, previous embolic events, type of replacement device, and persistent postoperative fever. RESULTS Clinical and echocardiographic follow-up was 97.36% complete, mean follow-up time was 53.2+/-3.4 months. Recurrent endocarditis developed in 58 cases (22.5%). Variables predicting recurrence were prosthetic endocarditis (p = 0.00001), positive valve culture (p = 0.0039), and persistence of fever at the seventh postoperative day (p = 0.000001). CONCLUSIONS Correct protocols of antibiotic therapy guided by microbiology may reduce the incidence of recurrent endocarditis to allow for surgery on sterile tissues and to prevent prosthetic infection. Recurrence rate is not affected by the choice of valve substitute, but can be prevented by complete surgical debridement.

Preliminary experience with the smooth muscle troponin-like protein, calponin, as a novel biomarker for diagnosing acute aortic dissection

AIMS The early diagnosis of acute aortic dissection (AD) remains challenging. We sought to determine the utility of the troponin-like protein of smooth muscle, calponin, as a diagnostic biomarker of acute AD. METHODS AND RESULTS Immunoassays against calponin (acidic, basic, and neutral isoforms) were developed and the levels were compared in a convenience sample of 59 patients with radiographically proven AD [34 males, age 59 +/- 15 (SD) years] vs. 158 patients suspected of having AD at presentation (116 males, age 63 +/- 15 years) but whose final diagnosis was not AD. Basic calponin, which is the most specific and abundant in smooth muscle, and acidic calponin, respectively, showed greater than two-fold and three-fold elevations in patients with acute AD. Diagnostic performance as determined by receiver-operating characteristics curve analysis showed that both acidic and basic calponin have the potential to detect AD in the first 24 h [respective areas under the curve (AUCs) 0.63 and 0.58], with superior performance of basic calponin (when compared with acidic) in the initial 6 h (respective AUCs 0.63 and 0.67). CONCLUSION Circulating calponin levels were elevated in acute AD compared with controls. These biomarkers have the potential for use as an early diagnostic biomarker for acute AD.

Off-pump coronary artery bypass surgery versus standard linear or pulsatile cardiopulmonary bypass: endothelial activation and inflammatory response

OBJECTIVE Poor outcomes after coronary artery bypass grafting (CABG) have been linked to perioperative endothelial activation and systemic inflammatory responses. The use of pulsatile cardiopulmonary bypass (PCPB) or off-pump CABG (OPCABG) may minimise these phenomena. We compared biochemical and clinical outcomes among patients who underwent CABG with PCPB, CABG with linear CPB (LCPB) or OPCABG. METHODS Sixty consecutive patients undergoing isolated elective CABG were prospectively randomised trial to receive pulsatile CPB (group A, 20 patients), linear CPB (group B, 20 patients) or OPCABG (group C, 20 patients). Levels of proinflammatory cytokines (interleukins-2, -6, and -8), anti-inflammatory cytokines (interleukin-10) and endothelial markers (vascular endothelial growth factor (VEGF), monocyte chemo-attractant protein (MCP)-1) were measured before, during and after surgery. RESULTS VEGF and MCP-1 levels increased significantly during surgery in all groups, but they increased the least and were the lowest overall with OPCABG. They rose most and peaked overall with LCPB. Interleukin-2 levels remained stable during OPCABG but decreased equally during PCPB and LCPB. Interleukin-6 and -8 levels rose significantly during both types of CPB versus OPCABG. Interleukin-10 levels increased significantly in all groups during surgery, but they rose least and were the lowest overall with OPCABG and rose most and were the highest overall with PCPB. Intubation times, intensive care unit (ICU) stay and hospital stay were significantly longer in the LCPB group than the other two groups. CONCLUSIONS LCPB appears to promote endothelial activation and cytokine secretion, which may delay recovery. OPCABG was associated with slight endothelial activation and cytokine response. PCPB significantly attenuates endothelial/cytokine leakage, resulting in hospital outcomes comparable with those after OPCABG.

Impact of clonidine administration on delirium and related respiratory weaning after surgical correction of acute type-A aortic dissection: results of a pilot study

Delirium and transient neurologic dysfunctions (TND) often complicate the postoperative course after surgery for acute type-A aortic dissection (AAD). We evaluated the role of clonidine on neurological outcome and respiratory function in 30 consecutive patients undergoing surgery for AAD. Patients were prospectively randomized to receive either clonidine (0.5 microg/kg bolus, followed by continuous infusion at 1-2 microg/kg/h) or placebo (NaCl 0.9%) in on starting and throughout the weaning period from the mechanical ventilation. Incidence of delirium and TND, Delirium Detection Score (DDS), weaning parameters [respiratory rate to tidal volume ratio - f/VT; pressure-frequency product (PFP); partial pressure of arterial oxygen to fractional inspired oxygen concentration (PaO(2)/FiO(2)); partial pressure of carbon dioxide (PaCO(2))], weaning duration and intensive care unit (ICU) length of stay were recorded. The two groups were similar for preoperative and operative variables and also for the incidence of postoperative complications. DDS was lower in the clonidine group (P<0.001). Patients weaned with clonidine showed lower f/VT and PFP, higher PaO(2)/FiO(2) and PaCO(2), lower DDS, weaning period and the related ICU length of stay (P<0.001). This was further confirmed in patients developing delirium/TND. Intravenous clonidine after surgery for AAD reduces the severity of delirium, improves the respiratory function, shortens the weaning duration and the ICU length of stay.