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Michael J Mack

Publications and source records attributed to Michael J Mack.

At least 37 records · Page 2Linked to original sources
PubMed2005

Improvement of renal dysfunction by conversion from calcineurin inhibitors to sirolimus after heart transplantation.

BACKGROUND: Chronic renal dysfunction is a common occurrence after heart transplantation in patients treated with calcineurin inhibitors (CIs). We evaluated the renal-sparing effects of converting stable heart transplant patients with renal dysfunction from a CI to sirolimus. METHODS: Beginning in 2000, heart transplant patients with renal dysfunction were converted from a CI to sirolimus. CI was abruptly discontinued and sirolimus added at 5 mg twice a day for 2 days and then 2 mg daily. The treatment goal was a 24-hour level of 6 to 12 ng/ml. All patients were also managed with mycophenolate mofetil (MMF) at 1,000 mg twice daily. RESULTS: Eighty from a total of 235 cardiac transplant patients were converted to sirolimus. The average time post-transplant for conversion was 4.78 years (range 3 days to 16 years). The average age at transplant was 55.43 years (range 15 to 70). At a mean of 304 days post-conversion, the mean serum creatinine (sCr) decreased from 2.04 +/- 0.57 mg/dl pre-conversion to 1.64 +/- 0.48 mg/dl (p < 0.001). In patients whose sCr was <2.5 mg/dl before conversion, the mean SCr level decreased from 1.81 +/- 0.39 to 1.62 +/- 0.5 mg/dl post-conversion (p = 0.01), with no patient developing end-stage renal disease (ESRD). Four patients with sCr > or =2.5 developed ESRD requiring dialysis despite conversion. In the remaining 15 patients with sCr > or =2.5 mg/dl, the sCr decreased from 2.85 +/- 0.29 to 1.73 +/- 0.43 mg/dl (p = 0.001). CONCLUSIONS: Conversion to sirolimus from CI is safe and has a renal-sparing effect in the management of heart transplant patients with chronic renal dysfunction. Based on these results, sirolimus has a role as a first-line immunosuppressive agent in heart transplant patients with renal dysfunction.

Adolescent↗
PubMed2005

Comparing on-pump and off-pump coronary artery bypass grafting: numerous studies but few conclusions: a scientific statement from the American Heart Association council on cardiovascular surgery and anesthesia in collaboration with the interdisciplinary working group on quality of care and outcomes research.

One of the most hotly debated and polarizing issues in cardiac surgery has been whether coronary artery bypass grafting (CABG) without the use of cardiopulmonary bypass or cardioplegia (off-pump CABG, or OPCAB) is superior to that performed with the heart-lung machine and the heart's being chemically arrested (standard CABG). Various clinical trials are reviewed comparing the 2 surgical strategies, including several large retrospective analyses, meta-analyses, and the randomized trials that address different aspects of standard CABG and OPCAB. Although definitive conclusions about the relative merits of standard CABG and OPCAB are difficult to reach from these varied randomized and nonrandomized studies, several generalizations may be possible. Patients may achieve an excellent outcome with either type of procedure, and individuals' outcomes likely depend more on factors other than whether they underwent standard CABG or OPCAB. Nevertheless, there appear to be trends in most studies. These trends include less blood loss and need for transfusion after OPCAB, less myocardial enzyme release after OPCAB up to 24 hours, less early neurocognitive dysfunction after OPCAB, and less renal insufficiency after OPCAB. Fewer grafts tend to be performed with OPCAB than with standard CABG. Length of hospital stay, mortality rate, and long-term neurological function and cardiac outcome appear to be similar in the 2 groups. To definitively answer the remaining questions of whether either strategy is superior and in which patients, a large-scale prospective randomized trial is required.

American Heart Association↗
PubMed2005

The PRoject of Ex-vivo Vein graft ENgineering via Transfection IV (PREVENT IV) trial: study rationale, design, and baseline patient characteristics.

BACKGROUND: Coronary artery bypass graft (CABG) surgery with autologous vein graft (VG) conduit is one of the most frequently performed operations in the United States. Unfortunately, many VGs become occluded during long-term follow-up largely because of neointimal hyperplasia. A novel approach to preventing neointimal hyperplasia is with the double-stranded oligonucleotide edifoligide (Corgentech Inc, South San Francisco, Calif). Edifoligide inhibits E2F, a transcription factor that activates cell-cycle genes responsible for neointimal hyperplasia. METHODS: PREVENT IV is a phase-III, multicenter, randomized double-blind placebo-controlled trial of ex vivo treatment of autologous VGs with edifoligide in patients undergoing initial CABG surgery. The primary end point is VG failure, defined as death or > or =75% stenosis in a treated VG at 12- to 18-month angiographic follow-up. Secondary end points include major adverse cardiac events through at least 5 years and adverse events through 30 days. RESULTS: Enrollment of 3014 patients from 107 sites was completed on October 22, 2003. The baseline and procedural characteristics of the PREVENT IV population are generally well matched to a contemporary population of patients undergoing initial CABG from the Society of Thoracic Surgeons National Database. Angiographic follow-up is ongoing and scheduled to be completed in March 2005. CONCLUSIONS: The PREVENT IV data will establish whether VG pretreatment with an E2F transcription factor decoy, edifoligide, can improve graft patency and reduce the long-term morbidity and mortality of patients undergoing CABG surgery.

Aged↗
PubMed2005

Invited commentary.

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Anastomosis, Surgical↗
PubMed2005

Does reporting of coronary artery bypass grafting from administrative databases accurately reflect actual clinical outcomes?

OBJECTIVES: Quality assessment of coronary artery bypass grafting has traditionally been performed with data from clinical databases. Administrative databases that rely primarily on information collected for billing purposes increasingly have been used as tools for public reporting of outcomes quality. The correlation of administrative data with clinical data for clinical quality assessment has not been confirmed. METHODS: With data from a clinical database, we analyzed the outcomes of all patients who underwent coronary artery bypass grafting surgery in 1 hospital between 1999 and 2001. This information was collected before, during, and after the surgery and hospitalization by designated clinical individuals involved with the patient's care and then entered into an audited clinical database (The Society of Thoracic Surgeons National Cardiac Database). These data were then compared with administrative data collected on the same cohort of patients for the number of procedures performed and mortality rate as reported by the federal government (Medical Provider Analysis and Review), state government (Texas Health Care Information Council), hospital system (HCA, Inc, Casemix Database), and an internet Web site (healthgrades.com). Data were analyzed on the basis of the population reported, definitions used, risk assessment algorithms, and case volumes. RESULTS: By using the audited The Society of Thoracic Surgeons database as the standard and aggregating the reporting of case volumes by the inclusion criteria of various sources of administrative data, we found variances in the reported procedure volumes and mortality. Case volumes were overreported by as much as 21% in all patients and underreported by up to 16% or more in Medicare patients. Mortality in administrative data exceeded that reported in clinical data by 21%. Reasons for variances included time period reported (calendar vs fiscal year), population reported (all patients, Medicare patients, Medicare patients aged >/= 65 years), date used for the patient record captured (date of surgery, discharge), and the definition of mortality. Different proprietary risk-adjusting algorithms used magnified variances with risk-adjusted mortality exceeding the Society of Thoracic Surgeons data by as much as 61%. CONCLUSIONS: Substantial variability of reported outcomes is seen in administrative data sets compared with an audited clinical database in the end points of the number of procedures performed and mortality. This variability makes it challenging for the nonclinician unfamiliar with outcomes analysis to make an informed decision.

Aged↗
PubMed2005

Routine immediate extubation after off-pump coronary artery bypass surgery: 514 consecutive patients.

OBJECTIVE: The purpose of this study was to evaluate the feasibility of routine immediate extubation in patients undergoing off-pump coronary artery bypass surgery. DESIGN: Case series. SETTING: Private hospital. PARTICIPANTS: Five hundred forty-eight consecutive patients undergoing off-pump coronary bypass surgery, representing 5 years of a single anesthesiologist's practice, were evaluated for routine immediate extubation. Thirty-four patients were excluded because they were already intubated, in preoperative cardiogenic shock, or converted to on-pump during the procedure. INTERVENTION: Patients received general anesthesia or general anesthesia plus thoracic epidural analgesia (25%) and underwent off-pump coronary bypass surgery. MEASUREMENTS AND MAIN RESULTS: All 514 patients who were intended to be immediately extubated were expeditiously extubated in the operating room. The numbers of reintubations, morbidity, and mortality were low. CONCLUSIONS: Routine immediate extubation of most off-pump coronary artery bypass patients appears feasible and most probably safe.

Aged↗
PubMed2005

Mitral valve surgery using the classical 'heartport' technique.

BACKGROUND AND AIM OF THE STUDY: Mitral surgery in selected patients using femoral cannulation, percutaneous retrograde cardioplegia and endoballoon aortic occlusion with a 4-5 cm thoracotomy is felt to carry a higher operative risk than sternotomy with conventional cannulation. Herein, the authors compared their experience of the first 117 'Heartport' (HP) patients with a computer-matched group of sternotomy approach surgical patients (SP) to assess operative risk and 30-day outcome. METHODS: Data were extracted from the authors' STS certified, audited database on 117 patients based on an intention to treat. Between December 1997 and December 2004, a total of 92 isolated mitral valve (MV) repair (HP-MVRpr) and 25 isolated MV replacement (HP-MVR) procedures was conducted using Heartport. The patients were matched 1:1 (by age +/-7 years, cerebrovascular disease, inotrope use, and ejection fraction +/- 5%) to a control SP group. Operative and 30-day outcomes were measured. RESULTS: No parameter showed any significant difference in 30-day outcome between the HP and SP groups, except for an increase in cross-clamp and perfusion times. Two patients in the HP-MVRpr group required conversion to sternotomy for repair of coronary sinus perforation, and one patient was repaired without conversion. Surgery in one HP-MVRpr patient was aborted due to limited aortic dissection, but successful repair was carried out later with a conventional approach. No patient required conversion to sternotomy for improved exposure of the operative site. CONCLUSION: Despite a longer cross-clamp time, 'classical' HP MV surgery can be performed with no increased risk compared to conventional MV surgery. Catheter and endoballoon complications were rare even in the early experience, and conversion to sternotomy was unusual and safely performed with this approach.

Adult↗
PubMed2004

On-pump versus off-pump coronary artery bypass surgery in a matched sample of women: a comparison of outcomes.

BACKGROUND: Women have consistently higher mortality and morbidity than men after coronary artery bypass grafting (CABG). Whether elimination of cardiopulmonary bypass and performance of coronary artery bypass grafting off-pump (OPCAB) have a beneficial effect specifically in women has not been defined. METHODS AND RESULTS: From January 1998 through March 2002, 21 902 consecutive female patients at 82 hospitals underwent isolated CABG, as reported in an administrative database. Propensity score computer matching was performed based on 13 variables representing patient characteristics and preoperative risk factors to correct for and minimize selection bias. A total of 7376 (3688 pairs) women undergoing CABG surgery were able to be successfully matched. In a propensity score computer-matched cohort, multivariate logistic regression (odds ratio) revealed that women undergoing on-pump surgery had a 73.3% higher mortality (P=0.002) and a 47.2% higher risk of bleeding complications (P=0.019). CONCLUSIONS: In a retrospective analysis of women undergoing CABG, computer-matched to minimize selection bias, off-pump surgery led to decreased mortality and morbidity including bleeding complications.

Aged↗
PubMed2004

Experience with various surgical options for the treatment of atrial fibrillation.

BACKGROUND: New alternatives exist using various energy sources and lesion lines for the surgical treatment of atrial fibrillation (AF). The efficacy of these options compared to the cut-and-sew maze III procedure is unknown. METHODS: From August 1996 to August 2003, 79 patients have undergone a procedure for AF, with 70 patients currently more than 3 months postsurgery. The patients (58 continuous, 12 paroxysmal) underwent a surgical procedure for AF, lone AF (12) and with concomitant procedures (58). Techniques included cut and sew (23), bipolar radiofrequency (RF) (28) and unipolar-RF (10), and cryothermy (9). Lesions included maze III (46), pulmonary vein isolation (16), and pulmonary vein isolation plus mitral annular connecting line only (8). RESULTS: Follow-up was complete in 58 (83%) of 70 patients at a mean time of 595 +/- 750 days (range, 24-2530 days). The operative mortality was 0% in lone AF patients and 7.1% (5/70) in patients undergoing concomitant procedures. Need for perioperative pacemaker was 22.9%. Overall, normal sinus rhythm (NSR) was restored in 82.7% of patients, with success in 83.3% (10/12) lone procedures and 82.6% (38/46) concomitant procedures ( P = NS); the rate of continuous AF was 85.1% (40/47) and SR with paroxysmal fibrillation was 72.7% (8/11) ( P = NS). Traditional maze was successful in 80.6% (29/36) patients, pulmonary vein isolation was successful 93.3% (14/15), and left-sided maze in 71.4% (5/7) ( P = NS). Cut and sew procedures were successful in 88.2% (15/17), RF-bipolar in 84.0% (21/25), RFunipolar in 77.8% (7/9), and cryothermy in 71.4% (5/7) ( P = NS). Energy source, lesion set, AF duration, and lone/concomitant procedure were the factors subjected to logistic regression analysis. No factors were predictive of achieving postoperative NSR. CONCLUSIONS: Our early experience with newer surgical techniques employing different energy sources and fewer incision lines suggests that the success rate may approach the results obtained with traditional cut-and-sew Cox-maze III procedures.

Atrial Fibrillation↗
PubMed2004

Thoracoscopic sympathectomy for hyperhidrosis: indications and results.

BACKGROUND: Hyperhidrosis can cause significant professional and social handicaps. Although treatments such as oral medication, botox, and iontophoresis are available, surgical sympathectomy is being increasingly utilized. METHODS: Between January 1997 and December 2002, 180 patients with palmar, axillary, facial, or plantar hyperhidrosis underwent a thoracoscopic sympathectomy. Surgical technique evolved during our study period and included excision of the sympathetic ganglia at T(2), T(3), or T(4) depending on the location of the sweating using monopolar cautery. RESULTS: Patient demographics included 33% males (59/180) and 67% females (121/180), with a mean age of 29.2 years old (range 12 to 76 years old). Ethnic origin was 67% white (122/180), 19% Asian (34/180), 8% Black (14/180), and 6% Hispanic (10/180). Positive family history of hyperhidrosis was noted in 57%. Preoperatively, 49% patients (86/180) had palmar sweating only, 7% patients (12/180) axillary only, 24% patients (43/180) palmar and axillary, 16% patients (28/180) face/scalp only, and 7% patients (11/180) all of the above; additionally 69% patients (125/180) had plantar hyperhidrosis. All procedures were performed through 3-mm and 5-mm ports, and 98% (177/180) were completed as an outpatient procedure. Complications included a mild temporary Horner's Syndrome (n = 1; 0.5%), air leak requiring chest drainage (n = 9; 5%), and bleeding (n = 3; 1.6%) requiring thoracoscopic reexploration (n = 1) and chest drainage (n = 2). Success rates were palmar 100% (109/109), axillary 98% (48/49), and face/scalp 93% (26/28). Plantar hyperhidrosis responded with improvement in 82% (72/88) of all patients. Seventy-eight percent patients (96/123) experienced compensatory hyperhidrosis, usually affecting the stomach, chest, back, and neck. Overall satisfaction was 94% (139/148). CONCLUSIONS: Thoracoscopic sympathectomy is a safe and effective outpatient method for managing hyperhidrosis. Although overall satisfaction is high, patients should be fully informed about the potential for compensatory sweating.

Adolescent↗
PubMed2004

Current status and outcomes of coronary revascularization 1999 to 2002: 148,396 surgical and percutaneous procedures.

BACKGROUND: Current practice, trends, and early outcomes in patients undergoing surgical and percutaneous coronary interventions (PCI) are changing and subject to speculation. METHODS: 148,396 consecutive patients in 69 HCA, Inc hospitals who underwent either PCI or coronary artery bypass grafting (CABG) were tracked in the HCA Casemix Database from 1999 through the first quarter of 2002. Comorbid conditions, procedures, complications, and outcome variables were defined through International Classification of Diseases, Ninth Revision coding. Odds ratios (OR) for death and other procedure-related complications were estimated using logistic regression adjusting for age, sex, and 31 other patient clinical and procedural characteristics. RESULTS: Now 65.4% of all coronary revascularization is by PCI with a 6.8% annual rate of increase whereas CABG volume is declining by 1.9% per year. However the majority of these changes occurred between 1999 and 2000 with only small changes in the last 3 years. Coronary artery bypass grafting is still utilized primarily for multivessel disease (3.38 bypasses per patient) whereas PCI is predominately (83%) still limited to single-vessel intervention. Unadjusted mortality rates over the full 13-quarter period were 1.25% for PCI and 2.63% for CABG (p < 0.001), with PCI rates remaining constant and CABG mortality declining. Twenty-three percent of CABG is performed off pump with a lower mortality than conventional on-pump CABG (2.37% versus 2.69%, p < 0.001). Percutaneous coronary intervention patients have lower mortality (OR 0.51), and fewer acute renal failure (OR 0.39), neurologic (OR 0.12), and cardiac (OR 0.16) complications than CABG patients (p < 0.001). CONCLUSIONS: Interventions for coronary artery disease continue to rise primarily due to an increase in PCI. The volume of PCI continues to increase relative to CABG. Although adverse outcomes are higher after CABG, the proportion of multivessel disease treated is greater. The difference in adverse outcomes between CABG and PCI remains small and continues to decline.

Aged↗