Biomedical subjects

Michael R Petracek

Publications and source records attributed to Michael R Petracek.

6 recordsLinked to original sources

PubMed2006

Combined percutaneous coronary intervention and valve surgery.

PURPOSE OF REVIEW: This article reviews unique advantages emerging in valvular heart disease as the technology of invasive cardiology and cardiac surgery begin to merge. RECENT FINDINGS: Minimally invasive valve surgery is increasing in popularity and has helped to reduce morbidity. In addition, preoperative or intraoperative treatment of coronary artery disease by a percutaneous approach has simplified operations and allowed more liberal use of non-traditional incisions. SUMMARY: Percutaneous intervention with drug-eluting stents has provided early evidence for decreased restenosis and improved long-term patency rates. At the same time, cardiac surgery has moved toward less invasive approaches performed in new imaging arenas known as 'hybrid' operating rooms. Combining these technological advances is providing unique solutions to valvular heart disease also requiring revascularization, and will likely become the next horizon for strategies in cardiovascular medicine.

Cardiac Catheterization↗

PubMed2004

Transmyocardial revascularization: 5-year follow-up of a prospective, randomized multicenter trial.

BACKGROUND: In prospective randomized trials at 1 year, transmyocardial revascularization (TMR) provided superior relief of angina, decreased rehospitalizations, and improved exercise times. We evaluated 5-year mortality and angina class in "no-option" patients with diffuse coronary artery disease randomized to TMR or continued medical management. METHODS: Two hundred twelve patients with refractory class IV angina who were not candidates for conventional therapy were randomized to receive holmium:yttrium-aluminum-garnet TMR (n = 100) or continued medical management (n = 112) at nine centers. Follow-up included all-cause mortality along with angina class assessment by blinded evaluators. Mean follow-up was 5.7 +/- 0.8 years. RESULTS: Mean angina scores for TMR patients were 4.0 +/- 0.0 at baseline, 1.5 +/- 1.4 at 1 year, and 1.2 +/- 1.1 at a mean of 5 years (p < 0.001). After an average of 5 years, a significantly greater proportion of TMR than medical management patients experienced two or more class improvement in angina (88% versus 44%; p < 0.001). Kaplan-Meier intention-to-treat survival at 5 years was 65% versus 52% (TMR versus medical management; p = 0.05). Cumulative hazard curves demonstrated a significantly reduced risk of late death for TMR patients; average annual mortality beyond 1 year was 8% versus 13% (TMR versus medical management; p = 0.03). CONCLUSIONS: Five-year follow-up of prospectively randomized, no-option class IV angina patients demonstrated significantly increased Kaplan-Meier survival in patients randomized to TMR. The significant angina relief observed 12 months after sole therapy TMR was sustained long term and continued to be superior to that observed for patients maintained on continued medical management alone.

Angina Pectoris↗

PubMed2002

Prevalence and clinical course of pleural effusions at 30 days after coronary artery and cardiac surgery.

The present prospective study was designed to determine the prevalence of pleural effusion at approximately 28 days after cardiac surgery and their subsequent course. This consecutive case study included 389 patients; 312 had only coronary artery bypass graft surgery (CABG) surgery, 37 had both valve and CABG surgery, and 40 had only valve surgery. Chest radiographs were obtained approximately 28 days postoperatively. Patients were subsequently contacted by telephone 3, 6, and 12 months postoperatively and questioned about the presence of fluid in their chest and related symptoms. The prevalence of pleural effusions in the patients undergoing only CABG surgery (63%) or CABG surgery plus valve surgery (62%) was significantly (p = 0.05) higher than that in the patients undergoing valve surgery only (45%). The prevalence of effusions occupying more than 25% of the hemithorax was 9.7%. The primary symptom associated with these larger effusions was dyspnea. Chest pain and fever were uncommon. Over the 12-month follow-up, the effusions tended to resolve. In conclusion, the prevalence of pleural effusions occupying more than 25% of the hemithorax is approximately 10%, 28 days postoperatively. These larger pleural effusions produce dyspnea but not chest pain or fever, and most of the effusions disappear gradually over the subsequent months.

Coronary Artery Bypass↗

PubMed2002

Coronary artery bypass in patients 80 years and over: is off-pump the operation of choice?

BACKGROUND: Octogenarians are at increased risk for perioperative morbidity and mortality after coronary artery bypass. In this study we compared our experience with patients undergoing on-pump coronary artery bypass (CAB) and those undergoing off-pump coronary artery bypass (OPCAB) to assess outcomes. METHODS: We used hospital database analysis in patients 80 years and older who underwent nonemergent coronary artery bypass with (N = 169) and without (N = 60) cardiopulmonary bypass from January 1999 through June 2001. RESULTS: Both groups were at increased perioperative risk based on the Society of Thoracic Surgeons risk model (7.7% OPCAB vs 5.8% CAB, p = 0.03). There were no operative deaths in the OPCAB group but there were eight (4.7%) in the CAB group (p = NS). Perioperative stroke (0% OPCAB vs 7.1% CAB, p = 0.04), prolonged ventilation (1.7% OPCAB vs 11.8% CAB, p = 0.02), and transfusion rate (33% OPCAB vs 70.4% CAB, p < 0.001) were all lower in the OPCAB group. A shorter hospital stay (6.3 days OPCAB vs 11.5 days CAB, p < 0.001) resulted in lower hospital cost in the OPCAB group ($9,363 OPCAB vs $12,312 CAB, p < 0.001). CONCLUSIONS: In this study, off-pump coronary artery bypass grafting in elderly patients was associated with fewer complications, a shorter hospital stay, and lower hospital cost. Off-pump coronary artery bypass grafting may be the operation of choice for octogenarians requiring surgical myocardial revascularization.

Aged↗

PubMed2002

Hemodynamics and early clinical performance of the St. Jude Medical Regent mechanical aortic valve.

BACKGROUND: The St. Jude Medical Regent valve is the next-generation bileaflet aortic prosthesis, modified from the currently marketed St. Jude Medical mechanical valve to achieve a larger geometric orifice without changing the existing design of the pivot mechanism or blood-contact surface areas. The present study reports the hemodynamic and early clinical results of an ongoing multicenter trial investigating the performance of the Regent valve. METHODS: Between July 1998 and July 2001, 361 patients at 17 centers in North America and Europe underwent implantation of a Regent mechanical aortic valve prosthesis. Clinical status was prospectively recorded, and echocardiography with Doppler was performed at discharge and at 2 months, 6 months, 1 year, and 2 years after operation. RESULTS: Follow-up to date is 300 patient-years (average, 0.8 +/- 0.7 years per patient; range, 0.0 to 2.7 years). There were low rates of clinical adverse events. Mean gradient at 6 months was 9.7 +/- 5.3 mm Hg, 7.6 +/- 5.2 mm Hg, 6.3 +/- 3.7 mm Hg, 5.8 +/- 3.4 mm Hg, and 4.0 +/- 2.6 mm Hg, respectively, for 19-mm, 21-mm, 23-mm, 25-mm, and 27-mm valves; effective orifice area was 1.6 +/- 0.4 cm2, 2.0 +/- 0.7 cm2, 2.2 +/- 0.9 cm2, 2.5 +/- 0.9 cm2, and 3.6 +/- 1.3 cm2, respectively. Indexed effective orifice area was equal to or greater than 1.0 cm2/m2 for all valve sizes. Left ventricular mass index decreased significantly between early postoperative (165.9 +/- 57.1 g/m2) and 6-month follow-up (137.9 +/- 41.0 g/m2; delta = -28.0 +/- 49.1 g/m2; p < 0.0001). CONCLUSIONS: The St. Jude Medical Regent aortic valve has excellent hemodynamics and early clinical results, with rapid and significant left ventricular mass regression. Long-term clinical assessment is ongoing.

Adult↗

PubMed2002

Assessing options for the small aortic root.

Valve selection for the small aortic root is a multifactorial process. Considerations include the effective orifice (EOA) of the implanted valve, annular size, body surface area (BSA), and valvular outflow tract of each patient. To decide if a valve is adequate for a patient, the valve EOA and patient BSA are used to calculate the indexed EOA (EOA/BSA). An indexed EOA <0.85 is associated with significant increases in mean systolic gradient with increase in cardiac output. The gradient remains low when indexed EOA is >0.85, leading to improved left ventricular mass reduction and decreased long-term risk of arrhythmias, congestive heart failure, and death. Biologic valves are usually used in patients aged over 65 years. Stented biologic valves tend to have a low EOA for their size. A 21-mm pericardial valve has an indexed EOA of 0.81 when implanted in a 1.6-m, 58-kg woman, and 0.69 in a 1.7-m, 72-kg man. Stentless valves (xenograft and homograft) have excellent EOAs and consequently very low gradients with good ventricular mass reduction. This allows for insertion of a larger valve, and results in more normal opening and flow dynamics. Hence, the best approach in over 65-year-old aortic valve patients when using a biologic valve is a stentless subcoronary implant. If this is not possible for anatomic reasons, a stented valve with an indexed EOA >0.85 is the best alternative. An option is root replacement with a xenograft or homograft, but the operative risk is significantly increased. The decision in younger patients (aged <65 years) is more complex. In-vivo EOAs for mechanical valves vary greatly; the St. Jude HP and Regent valves have consistently excellent EOAs. Recent results with the St. Jude Regent valve show gradients and left ventricular mass reduction close to those for stentless biologic valves. In a small aortic annulus, the decision must be made to use a more efficient valve (e.g. the Regent) or a biologic stentless valve, to perform annular enlargement (increasing surgical risk), or to tilt the stented valve to be supra-annular in the non-coronary cusp. The subvalvular outflow tract should not be ignored. Septal hypertrophy is not uncommon, and may increase the gradient across the outflow tract just below the valve. Finally, suture techniques (e.g. pledgetted versus interrupted simple sutures) can affect the long-term gradient. Pledgetted sutures can draw tissue underneath the valve and reduce the EOA. In conclusion, multiple factors must be evaluated when deciding which valve to use as a replacement in the small aortic root. These include patient age, lifestyle, pregnancy status, and drug compliance, as well as the indexed EOA of available prosthetic valves and the surgical procedure required for implant.

Adult↗