Designing Depression Screening Chatbots

Advances in voice recognition, natural language processing, and artificial intelligence have led to the increasing availability and use of conversational agents (chatbots) in different settings. Chatbots are systems that mimic human dialogue interaction through text or voice. This paper describes a series of design considerations for integrating chatbots interfaces with health services. The present paper is part of ongoing work that explores the overall implementation of chatbots in the healthcare context. The findings have been created using a research through design process, combining (1) literature survey of existing body of knowledge on designing chatbots, (2) analysis on state-of-the-practice in using chatbots as service interfaces, and (3) generative process of designing a chatbot interface for depression screening. In this paper we describe considerations that would be useful for the design of a chatbot for a healthcare context.

Bactrocera oleae-induced olive VOCs routing mate searching in Psyttalia concolor males: impact of associative learning

Olfaction is a key sense routing foraging behaviour in parasitoids. Preferences for food, mate and host stimuli can be innate in parasitic wasps. Alternatively, learning-mediated mechanisms play a crucial role. Females of the braconid parasitoid Psyttalia concolor exploit olfactory cues arising from tephritid hosts and related microhabitats. However, little is known on the olfactory stimuli routing males searching for mates. In this study, we focused on the attractiveness of Bactrocera oleae-induced olive volatiles towards P. concolor males. Furthermore, we evaluated learning occurrence in virgin males, when trained for selected unattractive volatile organic compounds (VOCs) associated with mate rewards. (E)-β-Ocimene, α-pinene and limonene attracted virgin males in Y-tube bioassays. Unattractive VOCs evoked positive chemotaxis after associative learning training. P. concolor males exposed to VOCs during a successful or unsuccessful mating, showed short-term preference for these VOCs (<1 h). However, memory consolidation was strictly dependent on reward value. Indeed, males experiencing a successful mating showed a fast consolidation into protein dependent long-term memory, appearing after 24 h. On the other hand, males experiencing a less valuable training experience (i.e. unsuccessful courtship), did not show consolidated memory after 24 h. Overall, our findings suggest that P. concolor virgin males may exploit VOCs from the host microhabitat to boost their mate searching activity, thus their reproductive success. However, since learning is a costly process, P. concolor males retained durable memories just in presence of a valuable reward, thus avoiding maladaptive behaviours.

A biopsy of Breast Cancer mobile applications: state of the practice review

BACKGROUND

Breast cancer is the most common cancer in women. The use of mobile software applications for health and wellbeing promotion has grown exponentially in recent years. We systematically reviewed the breast cancer apps available in today's leading smartphone application stores and characterized them based on their features, evidence base and target audiences.

METHODS

A cross-sectional study was performed to characterize breast cancer apps from the two major smartphone app stores (iOS and Android). Apps that matched the keywords "breast cancer" were identified and data was extracted using a structured form. Reviewers independently evaluated the eligibility and independently classified the apps.

RESULTS

A total of 1473 apps were a match. After removing duplicates and applying the selection criteria only 599 apps remained. Inter-rater reliability was determined using Fleiss-Cohen's Kappa. The majority of apps were free 471 (78.63%). The most common type of application was Disease and Treatment information apps (29.22%), Disease Management (19.03%) and Awareness Raising apps (15.03%). Close to 1 out of 10 apps dealt with alternative or homeopathic medicine. The majority of the apps were intended for patients (75.79%). Only one quarter of all apps (24.54%) had a disclaimer about usage and less than one fifth (19.70%) mentioned references or source material. Gamification specialists determined that 19.36% contained gamification elements.

CONCLUSIONS

This study analyzed a large number of breast cancer-focused apps available to consumers. There has been a steady increase of breast cancer apps over the years. The breast cancer app ecosystem largely consists of start-ups and entrepreneurs. Evidence base seems to be lacking in these apps and it would seem essential that expert medical personnel be involved in the creation of medical apps.

Lentivirus-induced 'Smart' dendritic cells: Pharmacodynamics and GMP-compliant production for immunotherapy against TRP2-positive melanoma

Monocyte-derived conventional dendritic cells (ConvDCs) loaded with melanoma antigens showed modest responses in clinical trials. Efficacy studies were hampered by difficulties in ConvDC manufacturing and low potency. Overcoming these issues, we demonstrated higher potency of lentiviral vector (LV)-programmed DCs. Monocytes were directly induced to self-differentiate into DCs (SmartDC-TRP2) upon transduction with a tricistronic LV encoding for cytokines (granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4)) and a melanoma antigen (tyrosinase-related protein 2 (TRP2)). Here, SmartDC-TRP2 generated with monocytes from five advanced melanoma patients were tested in autologous DC:T cell stimulation assays, validating the activation of functional TRP2-specific cytotoxic T lymphocytes (CTLs) for all patients. We described methods compliant to good manufacturing practices (GMP) to produce LV and SmartDC-TRP2. Feasibility of monocyte transduction in a bag system and cryopreservation following a 24-h standard operating procedure were achieved. After thawing, 50% of the initial monocyte input was recovered and SmartDC-TRP2 self-differentiated in vitro, showing uniform expression of DC markers, detectable LV copies and a polyclonal LV integration pattern not biased to oncogenic loci. GMP-grade SmartDC-TRP2 expanded TRP2-specific autologous CTLs in vitro. These results demonstrated a simpler GMP-compliant method of manufacturing an effective individualized DC vaccine. Such DC vaccine, when in combination with checkpoint inhibition therapies, might provide higher specificity against melanoma.

Rehospitalization following compensable work-related tetraplegia

DESIGN

Descriptive study.

OBJECTIVES

To document the characteristics of rehospitalization following work-related tetraplegia, investigate risk factors for rehospitalization and identify opportunities for rehospitalization prevention.

SETTING

Workers' compensation administrative database with national coverage.

METHODS

The administrative database of a large workers' compensation provider was searched for work-related tetraplegia claims with dates of injury between 1 January 1989 and 31 December 1999. In all, 61 cases were identified where detailed rehospitalization information was available. Medical payment data were extracted, rehospitalization reasons were coded, and rates, costs and length of stay were calculated.

RESULTS

In all, 62% of cases were rehospitalized at some time during the period for which data were available. The average number of days the study group spent rehospitalized per year was 9.2 and the average annual cost was 14,197 US dollars. The most common reasons for rehospitalization were dermatological (23%), orthopedic (18%) and urological (14%). It was found that as many as 74% of the total number of days persons spent rehospitalized, 64% of the monies spent on rehospitalization, and 47% of rehospitalizations could have been prevented.

CONCLUSIONS

Consistent with earlier research, the ability to identify risk factors for rehospitalization was limited. However, the current study does highlight the extent to which rehospitalizations disrupt the lives of people with work-related tetraplegia and that a substantial proportion of rehospitalizations can be avoided.

SPONSORSHIP

The research was supported, in part, by a grant from the National Institute on Disability and Rehabilitation Research National Model SCI Systems (Grant no. H133N00024).

Work-related tetraplegia: cause of injury and annual medical costs

STUDY DESIGN

Descriptive study.

OBJECTIVE

To describe the demographics, cause of injury, and annual-paid medical costs for the 5 years following injury for cases of work-related tetraplegia.

SETTING

A single United States workers' compensation (WC) claims database.

METHODS

Tetraplegia cases with initial date of injury from 1 January 1989 to 31 December 1999 were selected by cross-referencing word search terms pertaining to body part injured and nature of injury. The main outcome measures were injury causes and annual-paid medical payments (adjusted to year 2000 medical consumer price index) of work-related tetraplegia by injury group for each year postinjury over a 5-year time period.

RESULTS

A total of 62 claimants with work-related tetraplegia injured between 1 January 1989 and 31 December 1999. The vast majority of those identified were male claimants (92%) and more than a quarter worked in the construction industry (26%). Other highly represented industries included transportation and retail (15% each), manufacturing (13%), and agriculture and utility (11% each). The majority of injuries were the result of falls (36%) and vehicular accidents (34%). The mean Year 1 cost was US dollars 560524 for those with a high-level tetraplegia (C2-4 ASIA A-C), US dollars 431033 for a low-level injury (C5-8 ASIA A-C), and US dollars 178041 for those with an ASIA D tetraplegia injury. The mean cost of subsequent years (Years 2-5) was US dollars 130992 for a high-level, US dollars 129250 for a low-level, and Us dollars 34352 for an ASIA D tetraplegia injury.

CONCLUSIONS

Mean costs for Year 1 postinjury in WC cases are similar to previously published estimates. Comparing the current results with those of previous spinal cord injury cost studies suggests that those with work-related tetraplegia may receive more injury-related paid medical benefits after the first year postinjury than cases who do not receive WC-supported benefits.

SPONSORSHIP

Supported, in part, by a grant from the National Institute on Disability and Rehabilitation Research (NIDDR) (Grant # H133N00024).

Services provided following compensable work-related tetraplegia

DESIGN

Descriptive study.

OBJECTIVE

To describe and compare the medical services provided following work-related tetraplegic spinal cord injury (SCI).

SETTING

Workers' compensation claims database.

METHODS

The administrative database of a workers' compensation provider was searched for work-related tetraplegia claims with dates of injury between 1 January 1989 and 31 December 1999. In total, 62 cases were identified and grouped by impairment category. Medical payment data were extracted and assigned to service categories.

RESULTS

Although the level of services was directly related to the severity of impairment, patterns were similar across categories; for example, the largest proportions of payments were associated with durable medical equipment (DME) and attendant care in each impairment category. DME, readmissions and attendant care services varied considerably from year to year and within impairment category. Payments for physician care and medications/supplies showed the least variation within impairment categories. Workers' compensation payments were similar to National Spinal Cord Injury Database (NSCID) payments for the first year following injury; however, in subsequent years, workers' compensation figures were much higher.

CONCLUSIONS

Differences in annual medical payment and services by impairment category appear to be primarily due to variations in DME, attendant care and readmission. Payment differences in relation to National SCI figures may be related to better capture of payments by the workers' compensation administrative database. In addition, results suggest broader coverage by workers' compensation for medical services and items related to independent living.

Emergency management of spontaneous coronary artery dissection

Six cases of spontaneous coronary arteries dissection are reported. In one patient, triple vessel spontaneous coronary artery dissection was identified. Another patient presented spontaneous left main coronary artery dissection. In one case we found the spontaneous dissection of the left anterior descending artery associated with distal aortic arch dissection. These conditions are very rare and may present a surgical dilemma. Causative factors and underlying pathology are clarified. Prompt diagnosis and surgical intervention is safe and effective. Early recognition of left main coronary artery dissection or three-vessel dissection is essential because urgent coronary artery bypass grafting may be life saving.

Concomitant carotid endarterectomy and coronary bypass surgery: should cardiopulmonary bypass be used for the carotid procedure?

BACKGROUND AND OBJECTIVES

With the increasing age of patients undergoing coronary artery bypass grafting (CABG), a greater number have associated clinically significant carotid disease. This study determined the morbidity and mortality for combined carotid endarterectomy (CEA)/CABG using cardiopulmonary bypass (CPB) for both procedures versus a combined approach using CPB only during CABG.

PATIENTS AND METHODS

Between 1993 and 2000, 65 patients (Group I) underwent combined CEA and CABG using CPB for both surgical procedures and 88 patients (Group II) underwent combined CEA and CABG using CPB only during CABG. The demographic, clinical, and carotid and coronary angiographic data were similar between groups. In Group I, 22 (33.8%) patients and 32 (36%) patients in Group II presented with contralateral carotid artery stenosis.

RESULTS

CPB time was significantly longer in Group I, 127+/-21 minutes versus 98+/-11 minutes in Group II patients (p = 0.001). The incidence of surgical revision for bleeding and deep sternal wound infection was higher in Group I patients, 2 (3%) versus 1 (1.1%) and 5 (7.7%) versus 2 (2.2%), respectively, but not significant. Hospital mortality in Group I was 6% (4 patients) versus 5.7% (5 patients) in Group II (p = ns). Neurologic complications occurred in 4 (6%) and 5 (5.7%) patients in Group I and II, respectively (p = ns). Postoperative renal dysfunction was more common in Group I patients (22 [33.8%]) then in Group II patients 16 (19%) (p = 0.04). Of these patients, (16 [19%]) 8 (12.3%) in Group I and 6 (6.8%) in Group II required postoperative ultrafiltration (p = ns). Infectious complications were more frequent in Group I patients, 5 (7.7%) versus 2 (2.3%), but not statistically significant (p = ns). Overall actuarial survival at 1, 3, and 5 years, including all deaths, was 92%, 88%, and 82% in Group I versus 93%, 86%, and 81% in Group II (p = ns). Overall freedom from stroke at 5 years was 87.5% in Group I and 86.4% in Group II.

CONCLUSIONS

We conclude that combined CEA/CABG using CPB only during the myocardial revascularization procedure remains the technique of choice in patients with coronary and carotid artery disease, offering better outcome in terms of perioperative morbidity than a combined CEA/CABG using CPB for both procedures.

Restoration of patency after apparent occlusion of the lambda-graft's right branch

The "string sign" is a physiological and reversible response of the internal mammary artery (IMA) anastomosed to a moderately stenotic coronary artery. We describe a patient who presented postoperatively with a string sign phenomenon of the right branch of the lambda-composite graft. The graft regained full patency 32 months after the surgical procedure with progression of the native coronary artery stenotic lesion. This case demonstrates that under specific conditions, such as the progression of native coronary artery disease, a no-flow composite graft employing IMAs can only regain patency and functional status in the same way as in situ IMAs. These findings confirm that the IMA remains the conduit of choice not only for its long-term patency, but also for its physiological adaptation characteristics.

Beating heart myocardial revascularization on extracorporeal circulation in patients with end-stage coronary artery disease

OBJECTIVES

To evaluate in a cohort of ESCAD patients (pts) the effects of on-pump/beating-heart versus conventional CABG in terms of early and mid-term survival and morbidity and LV function improvement.

METHODS

Between January 1993 and December 2000, 78 (Group I) ESCAD pts underwent on-pump/beating-heart surgery. Mean age in Group I was 66.2+/-6 (58-79), NYHA and CCS class were 3.2+/-0.6 and 3.3+/-0.4 respectively, Myocardial viability index 0.69+/-0.1 (%), LVEF (%) 24.8+/-4, LVEDP (mmHg) 28.1+/-5.8 and LVEDD(mm) 69.5+/-6. Group II consisted in 78 ESCAD patients undergoing conventional CABG selected in a randomized fashion from an age, sex, and LVEF corrected group of patients. Mean age in Group II was 65.7+/-5 (57-78), NYHA 3.1+/-0.7, CCS 3.4+/-0.8, LVEF(%) 25+/-5, LVEDP(mmHg) 27.9+/-4.4 and LVEDD(mm) 69.2+/-7.2.

RESULTS

Postoperatively, 5(7.7%) patients died in Group I versus 7(11.5%) patients in Group II (P>0.1). CPB time resulted to be in Group II patients (P=0.001) and the mean distal anastomoses per patient was similar between groups (P=Ns). Perioperative AMI (P=0.039), LCOS (P=0.002), necessity for ultrafiltration (P=0.018) and bleeding>1000 ml (P=0.029) were significantly higher in Group II. None of the Group I patients underwent surgical revision for bleeding versus 8(10.3%) patients in Group II (P=0.011). At 6 months after surgery, the LV function improved significantly in Group I patients, demonstrated by an increased LVEF=27.2+/-4(%)(P=0.001), lower LVEDP=26.4+/-3(mmHg)(P=0.029) and LVEDD=67+/-4(mm) (P=0.004) instead of a lower LVEDD=66.8+/-6(mm)(P=0.032) versus the preoperative data in Group II. The actuarial survival at 1, 3 and 5 yr were 90, 82 and 71% in Group I and 89, 83 and 74% in Group II (P=Ns).

CONCLUSION

In ESCAD patients who may poorly tolerate cardioplegic arrest, on-pump/beating-heart CABG may be an acceptable alternative associated with lower postoperative mortality and morbidity. Such a technique offers a better myocardial and renal protection associated with lower postoperative complications due to intraoperative hypoperfusion.

Ischemic mitral valve regurgitation grade II-III: correction in patients with impaired left ventricular function undergoing simultaneous coronary revascularization

BACKGROUND AND AIM OF THE STUDY

Mitral valve regurgitation (MVR), occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction, is predictive of poor outcome. The study aim was to assess the feasibility of mitral valve surgery concomitant with coronary artery bypass grafting (CABG) in patients with ischemic MVR grade II-III and impaired LV function.

METHODS

Between January 1996 and July 2000, 99 patients with grade II and III ischemic MVR and LV ejection fraction (LVEF) 17-30% underwent either combined mitral valve surgery and CABG (group I, n = 49) or isolated CABG (group II, n = 50). LVEF (%), LV end-diastolic diameter (LVEDD; mm), LV end-diastolic pressure (LVEDP; mmHg), LV end-systolic diameter (LVESD; mm) respectively were 27.5+/-5, 67.7+/-7, 27.7+/-4 and 51.4+/-7 in group I versus 27.8+/-4, 67.5+/-6, 27.5+/-5 and 51.2+/-6 in group II. In group I, mitral valve repair was performed in 43 patients (88%) and replacement in six (12%).

RESULTS

Preoperative data analysis showed no difference between groups. Five patients (10%) died in group I, compared with six (12%) in group II (p = NS). Within six months of surgery, LV function and geometry improved significantly in group I versus group II (LVEF, p <0.001; LVEDD, p = 0.002; LVESD, p = 0.003, LVEDP, p <0.001); only mild improvements were seen in group II. The regurgitation fraction decreased significantly in group I patients after surgery (p <0.001). Cardiac index increased significantly in groups I and II (p <0.001 and p = 0.03, respectively). In group I at follow up, four of six patients undergoing mitral valve replacement died, compared with five of 43 patients (11.5%) undergoing mitral valve repair (p = 0.007). At three years, the overall survival in group II was significantly lower than in group I (p <0.009).

CONCLUSION

Both MV repair and replacement preserving subvalvular apparatus in patients with impaired LV function offered acceptable outcome in terms of morbidity and survival. Surgical correction of grade II-III MVR in patients with impaired LV function should be taken into consideration as it provides better survival and improves LV function.

Lambda graft with the radial artery or free left internal mammary artery anastomosed to the right internal mammary artery: flow dynamics

BACKGROUND

The aim of this study was to evaluate the outcome and flow dynamics of the lambda graft configuration, relative to a second arterial graft.

METHODS

From 1998 to 2000, 47 patients (mean age 55.5 +/- 4.7 years) with triple-vessel disease underwent arterial revascularization using the lambda graft. The in situ left internal mammary artery (LIMA) and right internal mammary artery (RIMA) were anastomosed to the left anterior descending (LAD) and obtuse marginal arteries, respectively. In 21 patients (group I) presenting proximal or middle-third LAD or right coronary (RC) arterial stenoses, the lambda graft was constructed by anastomosing the distal LIMA, as a free LIMA graft, to the RC and proximally to the in situ RIMA. In the other 26 patients (group II) presenting with middle-distal third LAD or RC arterial stenoses, the radial artery (RA) was used to construct the lambda graft. All patients underwent transthoracic echo color Doppler before and after an adenosine test at 1 week and 3 months after operation.

RESULTS

There were no hospital deaths. Overall, 47 lambda grafts were constructed. There was no difference between baseline and maximal flows and coronary flow reserve (CFR) between groups. CFR at IMA stems increased in both groups within 3 months versus 1 week [(LIMA)CFR = 2 +/- 0.3 vs 2.3 +/- 0.3 (p = 0.002) and (RIMA)CFR = 2.2 +/- 0.4 vs 2.5 +/- 0.3 (p = 0.009) in group I, and (LIMA)CFR = 2.12 +/- 0.33 vs 2.4 +/- 0.35 (p = 0.005) and (RIMA)CFR = 2.17 +/- 0.32 vs 2.52 +/- 0.26 (p = 0.001) in group II]. At 3 months versus 1 week, the (RIMA)diameter(i) (mm) at rest was 1.69 +/- 0.32 versus 1.48 +/- 0.2 (p = 0.015) in group I and 1.66 +/- 0.3 versus 1.47 + 0.2 (p = 0.01) in group II. At 6 +/- 2.4 months, all patients were free of angina.

CONCLUSIONS

These data, almost identical for free LIMA and RA to RIMA using the lambda graft, demonstrate that RIMA flow reserve is adequate for multiple coronary anastomoses irrespective of the second arterial graft.

Urgent surgical revascularization of unstable angina. Influence of double mammary arteries

OBJECTIVE

Aim of this study was to evaluate retrospectively: (1) the outcome in patients with unstable angina (UA) refractory to the medical therapy undergoing urgent-emergent CABG; (2) the influence of both IMAs employment.

PATIENTS AND METHODS

Between January 1995 and July 2000, 576 (28.5%) consecutive patients with UA underwent CABG procedure. 182 (31.6%, Group I) patients, presenting unstable hemodynamic or angina pectoris refractory to the maximal medical therapy, underwent urgent/emergent CABG. 397 (68.4%, Group II) patients, after the maximal medical therapy did not present angina's episodes or ECG alterations and underwent elective CABG procedure. Preoperative data were similar in the two groups. Both IMAs were used in 68 (37.4%) patients of I and 152 (38%) of II (P>0.05) to left side revascularization.

RESULTS

CAD extension was greater in Group I: 45 (24.7%) patients presented ischemia in >1 area vs 53 (13.5%) in II (P<0.001). Incidence of anteroseptal ischemia resulted significantly higher in I (P=0.017); left main coronary artery stenosis was present in 68 (37%) patients in I vs 108 (27%) in II (P=0.01). LV function resulted significantly depressed in I, demonstrated by a significantly lower LVEF (P<0.001), higher NYHA class (P<0.001) and preoperative incidence of IABP (P<0.001). Intraoperative data analysis did not reveal any difference between groups. Hospital mortality was 13 (7%) and 21 (5.3%) patients in I and II respectively (P=ns). Multivariate analysis of all preoperative and intraoperative variables revealed the age >65 years (P=0.01), congestive heart failure (P<0.001), LVEF<35% (P=0.03), >1 ischemic area (P=0.02) as strong predictors for poor overall survival, and LIMA (P=0.006) and both IMAs (P=0.001) as strong predictors for good overall survival. Actuarial survival at 1, 3 and 5 years resulted to be 98.5, 96.5 and 90% in I and 99, 96 and 92% in II (P=ns).

CONCLUSION

CABG has been associated with acceptable outcome in patients with UA which should be applied soonest possible in patients refractory to medical treatment. Total coronary revascularization and employment of both IMAs for left myocardial side are associated with low operative risk and incidence of complications, permit to have acceptable short and long-term outcome in this pool of patients.

Respiratory dysfunction after coronary artery bypass grafting employing bilateral internal mammary arteries: the influence of intact pleura

OBJECTIVE

To evaluate the role of intact pleurae regarding the postoperative respiratory functional status in patients undergoing coronary revascularization employing both internal mammary arteries (IMAs), according to the pedunculated or skeletonized technique (SKT) with opened or intact pleurae.

MATERIALS AND METHODS

Using both IMAs, 299 patients underwent elective coronary revascularization. They were randomized and divided into group I (n=82, undergoing IMA harvesting according to the SKT without opening the pleurae); group II (n=186, undergoing IMA harvesting according the pedunculated technique with open pleurae); and group III (n=31, undergoing IMA harvesting according the SKT with incidentally opened pleurae). There were no differences regarding the preoperative patient characteristics and the anaesthetic and surgical management.

RESULTS

There were two deaths in group I versus seven in group II and one in group III (P=ns). The number of total arterial myocardial revascularization and arterial composite grafts was significantly higher in groups I and III than in group II, (P<0.001 and P<0.005, respectively). The incidence of postoperative complications was similar between groups. Blood loss of >1000 ml was significantly higher in group II than group I (P<0.028); but the incidence of re-thoracotomy and blood transfusion was similar between groups. The mechanical ventilation time was significantly higher in groups II and III versus group I (P<0.018 and P<0.02, respectively). The incidence of prolonged ventilation (>24 h), pleural effusion, thoracocentesis and atelectasis, resulted in being significantly higher in group II than group I. The incidence of thoracocentesis was significantly higher in group III than group I. The pain score and analgesic requirements at 1-12 h after awakening were significantly higher in groups II and III versus group I, becoming similar after the chest tubes were removed. PaO(2) was significantly higher, and PaCO(2) and FiO(2) were significantly lower in group I than groups II and III at 1 and 4 h before extubation and at 1 and 4 h after extubation. PaO(2) and PaCO(2) became similar between groups at the 5th postoperative day.

CONCLUSIONS

According to our results, we may conclude that pleural integrity has beneficial effects on the respiratory functional status after coronary revascularization using both IMAs. A meticulous and more careful IMA harvesting approach significantly reduces the postoperative morbidity regarding the pulmonary functional status, and as a consequence, reduces the hospital costs.

Does on-pump/beating-heart coronary artery bypass grafting offer better outcome in end-stage coronary artery disease patients?

OBJECTIVES

The purpose of our study was to evaluate in a cohort of end-stage coronary artery disease (ESCAD) patients the effects of on-pump/beating-heart versus conventional coronary artery bypass grafting (CABG) requiring cardioplegic arrest. We report early and midterm survival, morbidity, and improvement of left ventricular (LV) function.

METHODS

Between January 1992 and October 1999, 107 (Group I) ESCAD patients underwent on-pump/beating-heart surgery and 191 (Group II) ESCAD patients underwent conventional CABG requiring cardioplegic arrest. Mean age in Group I was 65.8 +/- 6.5 years (58-79 years); New York Heart Association (NYHA) and Canadian Cardiovascular Society (CCS) classifications were 3.2 +/- 0.4 and 3.3 +/- 0.5, respectively. LV ejection fraction (LVEF) was 24.8% +/- 4%, LV end diastolic pressure (LVEDP) was 28.2 +/- 3.8 mmHg, and LV end diastolic diameter (LVEDD) was 69.6 +/- 4.6 mm. Mean age in Group II was 64.1 +/- 5 years (57-76 years), NYHA class was 3 +/- 0.6, CCS class was 3.4 +/- 0.4, LVEF was 26.2% +/- 4.3%, LVEDP was 27.2 +/- 3.4 mmHg, and LVED was 68 +/- 4.2 mm.

RESULTS

Preoperatively, Group I patients versus Group II patients had a markedly depressed LV function (LVEF, p = 0.006; LVEDP, p = 0.02; LVEDD, p = 0.003; and NYHA class, p = 0.002), older age (p = 0.012), and higher incidences of multiple acute myocardial infarction (AMI; p = 0.004), cardiovascular disease (CVD; p = 0.008), and chronic renal failure (CRH, p = 0.002). Cardiopulmonary bypass (CPB) time was longer in Group II patients (p = 0.028). The mean distal anastomosis per patient was similar between groups (p = NS). Operative mortality between Groups I and II was 7 (6.5%) and 19 (10%), respectively (p = NS). Perioperative AMI (p = 0.034), low cardiac output syndrome (LCOS; p = 0.011), necessity for ultrafiltration (p = 0.017), and bleeding (p = 0.012) were higher in Group II. Improvement of LV function within 3 months after the surgical procedure was markedly higher in Group I, demonstrated by increased LVEF (p = 0.035), lower LVEDP (p = 0.027), and LVEDD (p = 0.001) versus the preoperative data in Group II. The actuarial survivals at 1, 3, and 5 years were 95%, 86%, and 73% in Group I and 95%, 84%, and 72% in Group II (p = NS).

CONCLUSIONS

ESCAD patients with bypassable vessels to two or more regions of reversible ischemia can undergo safe CABG with acceptable hospital survival and mortality and morbidity. In higher risk ESCAD patients, who may poorly tolerate cardioplegic arrest, on-pump/beating-heart CABG may be an acceptable alternative associated with lower postoperative mortality and morbidity. Such a technique offers better myocardial and renal protection associated with lower postoperative complications.

Right Y-graft, a new surgical technique using mammary arteries for total myocardial revascularization

BACKGROUND

We report a new technique that consists of a right Y-graft using only skeletonized internal mammary arteries (IMA) for total arterial myocardial revascularization.

METHODS

This technique consists of anastomosing the in situ left IMA (LIMA) and right IMA (RIMA) to the left anterior descending and obtuse marginal artery, via the transverse sinus, respectively. The distal free LIMA was anastomosed to the right coronary artery and afterwards in a Y fashion to the RIMA stem. Eleven patients with triple-vessel disease underwent coronary artery bypass grafting using this technique. Postoperatively and at follow-up all patients underwent color Doppler contrast-enhanced transthoracic echocardiography (TTE) before and after an adenosine provocation test.

RESULTS

Overall, 33 IMA-coronary anastomoses were made and 11 right Y-grafts were constructed. At 1 week after operation color Doppler contrast-enhanced TTE before and after the adenosine provocation test, respectively, showed an increase in LIMA stem diameter of 0.31 mm and in mean flow 62 mL/min. Coronary flow reserve (CFR) was 2+/-0.3. The increase in RIMA stem diameter was 0.2 mm and in mean flow was 121.7 mL/min. Coronary flow reserve was 2.5+/-0.4. Only 1 patient demonstrated an anomalous Doppler pattern, suggesting a partial Y-graft closure.

CONCLUSIONS

Such a technique permits total myocardial revascularization using only mammary arteries and left ventricular perfusion from both IMAs simultaneously. The color Doppler contrast-enhanced TTE is a rapid, accurate, and noninvasive test allowing a good assessment of IMA patency.

Mid-term outcome of surgical coronary ostial plasty: our experience

The conventional coronary artery bypass procedure that uses venous or arterial conduit for isolated critical stenosis of the left main coronary artery (LMCA) restores a less physiological perfusion of the myocardium and uses an appreciable length of bypass material. Coronary ostial plasty has been described as an alternative surgical technique in proximal obstructive coronary artery disease without calcifications. Here we report 23 patients (15 males and 8 females aged 37-78 years; mean age 57 years) who underwent surgical ostial plasty. Ostial reconstruction with fresh pericardial patch was performed in all patients: 15 patients with LMCA stenosis, 6 patients with right coronary (RC) ostial stenosis, and 2 patients with both RC artery and LMCA stenosis. In seven cases, coronary artery bypass grafting was added for contralateral distal stenosis with a total of five arterial conduits and six venous grafts. One patient died; the ostial plasty and grafts were patent at necropsy. Thallium-201 myocardial scintigraphy under stress at 30 days to 6 months after operation demonstrated good myocardial perfusion in 21 of 22 patients. Coronary angiography at follow-up (49 +/- 8 months) demonstrated good surgical ostial plasty results in 21 of 22 patients and good coronary flow in 19 of 22 patients; angiographic study at mid-term follow-up revealed only one failure of the surgical ostial plasty technique associated with venous graft obstruction. In 2 other patients CABG failure due to venous graft obstruction (1 patient) or distal stenotic lesions of the left coronary artery (1 patient) was noted. The overall successful outcome of the surgical ostial plasty was 22 of 23. We believe that surgical angioplasty of the coronary ostia may be used in the presence of proximal noncalcified obstructive lesions as an alternative technique, which offers a more physiological revascularization; it also spares grafting material and allows subsequent percutaneous transluminal angioplasty or coronary artery bypass surgery.

Abdominal aortic aneurysms in heart transplanted patients

OBJECTIVE

In the AA's opinion, the dilatation of the abdominal aorta is not a contraindication to heart transplantation.

METHODS AND MATERIALS

From July 1994 to February 1998, 3 out of 80 heart transplanted patients, required a replacement of their abdominal aorta because of an infrarenal aortic aneurysm. The first patient (62 years old) did not have an aneurysm by time of heart transplantation: his aneurysm (5.1 cm wide) was resected 2 years later. The other two patients (m, 44 years old; m, 60 years old) had a dilatation of 3.1 and 3.5 cm of the abdominal aorta by time of cardiac transplantation: 15 months later, the aneurysms measured 5.8 and 7 cm, respectively, and had been resected. Two resections were performed through a retroperitoneal approach.

RESULTS

All 3 patients had uneventful postoperative course.

CONCLUSION

Before heart transplantation the aorta must be screened for dilatation or aneurysm, which can be enlarged by operation. Such lesions can be operated on, with low risks, and should not be a contraindication to heart transplantation.

Characterization of the hyperpolarization-activated current, I(f), in ventricular myocytes from human failing heart

BACKGROUND

Disease-associated electrophysiological alterations may contribute to the increased predisposition to arrhythmias of the hypertrophied or failing myocardium. An I(f)-like current is expressed in rat left ventricular myocytes (LVMs), its amplitude being linearly related to the severity of cardiac hypertrophy. Here, we report the occurrence and electrophysiological properties of I(f) in human LVMs.

METHODS AND RESULTS

LVMs were isolated from hearts of three male patients undergoing cardiac transplantation for terminal heart failure due to ischemic dilated cardiomyopathy. The patch-clamp technique was used to record I(f), ie, a barium-insensitive, cesium-sensitive, time-dependent increasing inward current elicited on hyperpolarization. Membrane capacitance was 244 +/- 27 pF (n = 25). I(f) occurred in all cells tested; its density measured at -120 mV was 2.1 +/- 0.3 pA/pF. Activation curves of I(f) (n = 24) were fitted by a Boltzmann function; the threshold was -55 mV; midpoint, -70.9 +/- 2.1 mV; slope, -5.4 +/- 0.3 mV; and maximal specific conductance, 19.6 +/- 2.5 pS/pF. I(f) blockade by extracellular cesium was voltage dependent. Reducing extracellular potassium concentration from 25 to 5.4 mmol/L caused a shift of the reversal potential from -12.7 +/- 0.5 to -24.8 +/- 2.1 mV and a 64% decrease of current conductance.

CONCLUSIONS

I(f) is present in human LVMs. Its electrophysiological characteristics resemble those previously described in hypertrophied rat LVMs and suggest that I(f) could be an arrhythmogenic mechanism in patients with severe heart failure.