Cardiac image fusion from stand-alone SPECT and CT: clinical experience

Myocardial perfusion imaging with SPECT (SPECT-MPI) and 64-slice CT angiography (CTA) are both established techniques for the noninvasive evaluation of coronary artery disease (CAD). Three-dimensional (3D) SPECT/CT image fusion may offer an incremental diagnostic value by integrating both sets of information. We report our first clinical experiences with fused 3D SPECT/CT in CAD patients. METHODS: Thirty-eight consecutive patients with at least 1 perfusion defect on SPECT-MPI (1-d adenosine stress/rest SPECT with (99m)Tc-tetrofosmin) and 64-slice CTA were included. 3D volume-rendered fused SPECT/CT images were generated and compared with the findings from the side-by-side analysis with regard to coronary lesion interpretation by assigning the perfusion defects to their corresponding coronary lesion. RESULTS: The fused SPECT/CT images added information on pathophysiologic lesion severity in 27 coronary stenoses (22%) of 12 patients (29%) (P<0.001). Among 40 equivocal lesions on side-by-side analysis, the fused interpretation confirmed hemodynamic significance in 14 lesions and excluded functional relevance in 10 lesions. In 3 lesions, assignment of perfusion defect and coronary lesion appeared to be reliable on side-by-side analysis but proved to be inaccurate on fused interpretation. Added diagnostic information by SPECT/CT was more commonly found in patients with stenoses of small vessels (P=0.004) and involvement of diagonal branches (P=0.01). CONCLUSION: In addition to being intuitively convincing, 3D SPECT/CT fusion images in CAD may provide added diagnostic information on the functional relevance of coronary artery lesions.

Benefits of cardiac surgery in octogenarians--a postoperative quality of life assessment

OBJECTIVE: Assessment of postoperative quality of life in patients over 80 years after cardiac surgery including coronary artery bypass grafting (CABG), aortic valve replacement (AVR) and combined procedures. METHODS: Quality of life of n=136 patients over 80 years at operation (82.3+/-2.1 years), undergoing isolated CABG in 61 patients (45%), isolated AVR in 34 patients (25%) and a combination of CABG and AVR in 41 patients (30%) between January 1999 and December 2003 was reviewed. Preoperatively 66.2% presented in NYHA-class III/IV or CCS-class III/IV. Mean ejection fraction (EF) was 59.5%+/-14.0 (range 25-90%). Quality of life assessment was performed via a Seattle Angina Questionnaire. Follow-up was 100% complete for a total of 890 days (69-1853 days). RESULTS: Five-year survival was 70% for the CABG group, 75% for the AVR group and 65% for the CABG/AVR group. Quality of life was remarkable in all of the three groups after surgery. Overall 97 patients (81%) were not or little disabled in their daily activity. One hundred and twelve patients (93%) were free or considerably less symptomatic. Seventy-eight patients or 65% reported to be very satisfied with their current quality of life and 112 patients (93%) felt very reassured to have continuous full access to medical treatment despite of their advanced age. CONCLUSIONS: A remarkable quality of life and important improvement in the functional status after cardiac surgery in patients over 80 paired with a satisfactory medium-term survival justify early intervention for heart disease in this age group. Therefore, referral practice for patients over 80 years for heart surgery should be handled liberally.

ECG-triggered muscular counterpulsation for treatment of low cardiac output

BACKGROUND: Skeletal muscular counterpulsation (MCP) has been used as a new noninvasive technique for treatment of low cardiac output. The MCP method is based on ECG-triggered skeletal muscle stimulation. The purpose of the present study was to evaluate acute hemodynamic changes induced by MCP in the experimental animal. METHODS: Eight anaesthetized pigs (43+/-4 kg) were studied at rest and after IV â-blockade (10 mg propranolol) before and after MCP. Muscular counterpulsation was performed on both thighs using trains (75 ms duration) of multiple biphasic electrical impulses with a width of 1 ms and a frequency of 200 Hz at low (10 V) and high (30 V) amplitude. ECG-triggering was used to synchronize stimulation to a given time point. LV pressure-volume relations were determined using the conductance catheter. After baseline measurements, MCP was carried out for 10 minutes at low and high stimulation amplitude. The optimal time point for MCP was determined from LV pressure-volume loops using different stimulation time points during systole and diastole. Best results were observed during end-systole and, therefore, this time point was used for stimulation. RESULTS: Under control conditions, MCP was associated with a significant decrease in pulmonary vascular resistance (-18%), a decrease in systemic vascular resistance (-11%) and stroke work index (-4%), whereas cardiac index (+2%) and ejection fraction (+6%) increased slightly. Pressure-volume loops showed a leftward shift with a decrease in end-systolic volume. After â-blockade, cardiac function decreased (HR, MAP, EF, dP/dt max), but it improved with skeletal muscle stimulation (HR +10% and CI +17%, EF +5%). There was a significant decrease in pulmonary (-19%) and systemic vascular resistance (-29%). CONCLUSIONS: In the animal model, ECG-triggered skeletal muscular counterpulsation is associated with a significant improvement in cardiac function at baseline and after IV â-blockade. Thus, MCP represents a new, non-invasive technique which improves cardiac function by diastolic compression of the peripheral arteries and veins, with a decrease in systemic vascular resistance and increase in cardiac output.

Mechanism of Ca(v)1.2 channel modulation by the amino terminus of cardiac beta2-subunits

L-type calcium channels are composed of a pore, alpha1c (Ca(V)1.2), and accessory beta- and alpha2delta-subunits. The beta-subunit core structure was recently resolved at high resolution, providing important information on many functional aspects of channel modulation. In this study we reveal differential novel effects of five beta2-subunits isoforms expressed in human heart (beta(2a-e)) on the single L-type calcium channel current. These splice variants differ only by amino-terminal length and amino acid composition. Single-channel modulation by beta2-subunit isoforms was investigated in HEK293 cells expressing the recombinant L-type ion conducting pore. All beta2-subunits increased open probability, availability, and peak current with a highly consistent rank order (beta2a approximately = beta2b > beta2e approximately = beta2c > beta2d). We show graded modulation of some transition rates within and between deep-closed and inactivated states. The extent of modulation correlates strongly with the length of amino-terminal domains. Two mutant beta2-subunits that imitate the natural span related to length confirm this conclusion. The data show that the length of amino termini is a relevant physiological mechanism for channel closure and inactivation, and that natural alternative splicing exploits this principle for modulation of the gating properties of calcium channels.

Effects of non-ionic iodinated contrast media on patient heart rate and pressures during intra-cardiac or intra-arterial injection

PURPOSE: To compare the effects on heart rate (HR), on left ventricular (LV) or arterial pressures, and the general safety of a non-ionic low-osmolar contrast medium (CM) and a non-ionic iso-osmolar CM in patients undergoing cardiac angiography (CA) or peripheral intra-arterial digital subtraction angiography (IA-DSA). MATERIALS AND METHODS: Two double-blind, randomized studies were conducted in 216 patients who underwent CA (n=120) or peripheral IA-DSA (n=96). Patients referred for CA received a low-osmolar monomeric CM (iomeprol-350, n=60) or an iso-osmolar dimeric CM (iodixanol-320; n=60). HR and LV peak systolic and end-diastolic pressures were determined before and after the first injection during left and right coronary arteriography and left ventriculography. Monitoring for all types of adverse event (AE) was performed for 24 h following the procedure. t-tests were performed to compare CM for effects on HR. Patients referred for IA-DSA received iomeprol-300 (n=49) or iodixanol-320 (n=47). HR and arterial blood pressure (BP) were evaluated before and after the first 4 injections. Monitoring for AE was performed for 4 h following the procedure. Repeated-measures ANOVA was used to compare mean HR changes across the first 4 injections, whereas changes after the first injection were compared using t-tests. RESULTS: No significant differences were noted between iomeprol and iodixanol in terms of mean changes in HR during left coronary arteriography (p=0.8), right coronary arteriography (p=0.9), and left ventriculography (p=0.8). In patients undergoing IA-DSA, no differences between CM were noted for effects on mean HR after the first injection (p=0.6) or across the first 4 injections (p=0.2). No significant differences (p>0.05) were noted in terms of effects on arterial BP in either study or on LV pressures in patients undergoing CA. Non-serious AE considered possibly CM-related (primarily headache and events affecting the cardiovascular and digestive systems) were reported more frequently by patients undergoing CA and more frequently after iodixanol (14/60 [23.3%] and 2/47 [4.3%]; CA and IA-DSA, respectively) than iomeprol (10/60 [16.7%] and 1/49 [2%], respectively). CONCLUSIONS: Iomeprol and iodixanol are safe and have equally negligible effects on HR and LV pressures or arterial BP during and after selective intra-cardiac injection and peripheral IA-DSA. CLINICAL APPLICATION: Iomeprol and iodixanol are safe and equally well tolerated with regard to cardiac rhythm and clinical preference should be based on diagnostic image quality alone.

Arginine vasopressin in advanced cardiovascular failure during the post-resuscitation phase after cardiac arrest

Arginine vasopressin (AVP) has been employed successfully during cardiopulmonary resuscitation, but there exist only few data about the effects of AVP infusion for cardiovascular failure during the post-cardiac arrest period. Cardiovascular failure is one of the main causes of death after successful resuscitation from cardiac arrest. Although the "post-resuscitation syndrome" has been described as a "sepsis-like" syndrome, there is little information about the haemodynamic response to AVP in advanced cardiovascular failure after cardiac arrest. In this retrospective study, haemodynamic and laboratory variables in 23 patients with cardiovascular failure unresponsive to standard haemodynamic therapy during the post-cardiac arrest period were obtained before, and 30 min, 1, 4, 12, 24, 48, and 72 h after initiation of a supplementary AVP infusion (4 IU/h). During the observation period, AVP significantly increased mean arterial blood pressure (58+/-14 to 75+/-19 mmHg, p < 0.001), and decreased noradrenaline (norepinephrine) (1.31+/-2.14 to 0.23+/-0.3 microg/kg/min, p = 0.03), adrenaline (epinephrine) (0.58+/-0.23 to 0.04+/-0.03 microg/kg/min, p = 0.001), and milrinone requirements (0.46+/-0.15 to 0.33+/-0.22 microg/kg/min, p < 0.001). Pulmonary capillary wedge pressure changed significantly (p < 0.001); an initial increase being followed by a decrease below baseline values. While arterial lactate concentrations (95+/-64 to 21+/-18 mg/dL, p < 0.001) and pH (7.27+/-0.14 to 7.4+/-0.14, p < 0.001) improved significantly, total bilirubin concentrations (1.12+/-0.95 to 3.04+/-3.79 mg/dL, p = 0.001) increased after AVP. There were no differences in the haemodynamic or laboratory response to AVP between survivors and non-survivors. In this study, advanced cardiovascular failure that was unresponsive to standard therapy could be reversed successfully with supplementary AVP infusion in >90% of patients surviving cardiac arrest.

Electroencephalographic changes after pediatric cardiac surgery with cardiopulmonary bypass: is slow wave activity unfavorable?

Pediatric cardiac surgery with cardiopulmonary bypass (CPB) is frequently associated with neurologic deficits. We describe the postoperative EEG changes, assess their possible causes, and evaluate their relevance to neurologic outcome. Thirty-one children and five neonates with congenital heart disease were included. EEG recording started after intubation and continued until 22-96 h after CPB. In addition to conventional analysis, spectral analysis was performed for occipital and frontal electrodes, and differences between pre- and postoperative delta power (delta-deltaP) were calculated. Maximum values of occipital delta-deltaP that occurred within 48 h after CPB were correlated with clinical variables and with perioperative markers of oxidative stress and inflammation. Occipital delta-deltaP correlated with frontal delta-deltaP, and maximum delta-deltaP correlated with conventional rating. Distinct rise of deltaP was detected in 18 of 21 children without any acute or long-term neurologic deficits but only in five of 10 children with temporary or permanent neurologic deficits. Furthermore, maximally registered delta-deltaP was inversely associated with duration of CPB and postoperative ventilation. Maximal delta-deltaP was also inversely associated with the loss of plasma ascorbate (as an index of oxidative stress) and plasma levels of IL-6 and IL-8. Slow wave activity frequently occurs within 48 h after CPB. However, our data do not support the notion that EEG slowing is associated with adverse neurologic outcome. This is supported by the fact that EEG slowing was associated with less oxido-inflammatory stress.

Upregulation of endothelin converting enzyme-1 in host liver during chronic cardiac allograft rejection

Endothelin regulates cytokine expression in vitro and in vivo. This study investigated the effects of chronic allograft rejection on hepatic endothelin-converting enzyme-1 (ECE-1) gene expression and endothelin-1 (ET-1) plasma clearance. Using the Lewis-F344 minor histocompatibility mismatch model of heterotopic cardiac transplantation, hepatic ECE-1 gene expression was measured by real-time polymerase chain reaction and host plasma clearance of ET-1 was measured 8 weeks after transplantation in the absence of immunosuppression. In animals undergoing allograft rejection, hepatic ECE-1 gene expression increased 2-fold (P < 0.05), whereas no effect of rejection on ET-1 clearance from plasma was observed. In summary, upregulation of ECE-1 gene expression occurs in the liver of the host during chronic allograft rejection. Because the liver represents both a key organ for cytokine production and for endothelin metabolism, increased hepatic ECE-1-mediated ET-1 synthesis may contribute to host responses and cytokine production during allograft rejection.

Transplantation of yeast-infected cardiac allografts: a report of 2 cases

For the first time in the literature to date, we report 2 cases of transplantation of yeast-infected cardiac allografts. In both cases, endocardial vegetations were observed before graft implantation. Microbiologic samples grew yeasts: Rhodotorula glutinis was found close to the left atrial appendage in the first case and Candida parapsilosis was identified in a vegetation located at the base of the tricuspid valve in the second case. We discuss the possible routes of donor organ infection and management of these 2 unusual cases.

Trastuzumab-associated cardiac adverse effects in the herceptin adjuvant trial

PURPOSE: The purpose of this analysis was to investigate trastuzumab-associated cardiac adverse effects in breast cancer patients after completion of (neo)adjuvant chemotherapy with or without radiotherapy. PATIENTS AND METHODS: The Herceptin Adjuvant (HERA) trial is a three-group, multicenter, open-label randomized trial that compared 1 or 2 years of trastuzumab given once every 3 weeks with observation in patients with HER-2-positive breast cancer. Only patients who after completion of (neo)adjuvant chemotherapy with or without radiotherapy had normal left ventricular ejection fraction (LVEF > or = 55%) were eligible. A repeat LVEF assessment was performed in case of cardiac dysfunction. RESULTS: Data were available for 1,693 patients randomly assigned to 1 year trastuzumab and 1,693 patients randomly assigned to observation. The incidence of trastuzumab discontinuation due to cardiac disorders was low (4.3%). The incidence of cardiac end points was higher in the trastuzumab group compared with observation (severe congestive heart failure [CHF], 0.60% v 0.00%; symptomatic CHF, 2.15% v 0.12%; confirmed significant LVEF drops, 3.04% v 0.53%). Most patients with cardiac dysfunction recovered in fewer than 6 months. Patients with trastuzumab-associated cardiac dysfunction were treated with higher cumulative doses of doxorubicin (287 mg/m(2) v 257 mg/m(2)) or epirubicin (480 mg/m(2) v 422 mg/m(2)) and had a lower screening LVEF and a higher body mass index. CONCLUSION: Given the clear benefit in disease-free survival, the low incidence of cardiac adverse events, and the suggestion that cardiac dysfunction might be reversible, adjuvant trastuzumab should be considered for treatment of breast cancer patients who fulfill the HERA trial eligibility criteria.

Acute myocardial infarction in early pregnancy: definition of myocardium at risk with noncontrast T2-weighted cardiac magnetic resonance

We report a case of a 34-year-old woman who had a left anterior wall myocardial infarction develop in the first trimester of pregnancy. Despite urgent and successful revascularization, she demonstrated persistent segmental wall motion abnormalities by transthoracic echocardiography. To manage this patient safely through pregnancy with a better definition of myocardium at risk, a cardiac magnetic resonance examination was performed. This identified a large territory of acutely edematous myocardium in addition to providing accurate volumetric measurements of left ventricular size and function. Because of her gravid state, gadolinium was not administered nor was it required to delineate the region of myocardium at risk.