Closure of prosthetic paravalvular mitral regurgitation with the Gianturco-Grifka vascular occlusion device.

Paravalvular regurgitation associated with prothetic mitral valves is often a consequence of infectious endocarditis. The condition is usually treated with debridement and repeat surgical valve replacement. However, repeated operations are associated with high risk. This report describes a case of successful transcatheter treatment of severe paravalvular mitral regurgitation and pulmonary edema in a patient in whom repeat mitral valve replacement was not believed possible.

Atherosclerotic renovascular disease: diagnosis and treatment.

The technical expertise and tools required to treat renovascular obstruction have become commonplace, and many series of patients revascularized with surgery, balloon angioplasty or endovascular stenting have been reported. Nevertheless, although hypertension and renal failure are easy to diagnose, their cause often remains elusive. Evidence is developing that patients with hypertension and atherosclerotic renal artery stenosis may often have hypertension and renovascular disease but not hypertension because of renovascular disease. As a result, diagnosis and therapy are increasingly directed towards the preservation of renal function, and the future of renal revascularization will depend on how well potential therapies address this goal.

Effect of renal artery stenting on renal function and size in patients with atherosclerotic renovascular disease.

BACKGROUND: Renal artery stenting is widely performed, but little is known about its effectiveness in preserving renal function and size in patients with renovascular disease and chronic renal insufficiency. We studied the effect of renal artery stenting on renal function and size in patients with obstructive renovascular disease and chronic renal insufficiency. METHODS AND RESULTS: Stent deployment was performed in patients with chronic renal insufficiency (creatinine >1.5 mg. dL(-1)) and global renovascular obstruction (bilateral renal artery stenosis or unilateral stenosis in the presence of a solitary or single functional kidney). The effect of renal artery stenting on renal function was assessed by comparing the slopes of the regression lines derived from the reciprocal of serum creatinine versus time plotted before and after stent deployment. Renal size was assessed by serial ultrasound of pole-to-pole kidney length. Stenting was successful in all 61 vessels in 33 patients. Twenty-five patients had complete follow-up (mean 20+/-11 months). Before stent deployment, all patients exhibited a negative slope, indicating progressive renal insufficiency. After stent deployment, the slopes were positive in 18 and less negative in 7 patients. Thus, the mean slope increased from -0.0079 to 0.0043 dL. mg(-1). mo(-1) (P:<0.001). Ultrasonography on 41 kidneys revealed preservation of size, with the kidney length measuring 10.4+/-1.4 cm at baseline and 10.4+/-1.1 cm at last follow-up (P:=NS). Patient survival at 20+/-11 months was 90%. CONCLUSIONS: In patients with chronic renal insufficiency and global obstructive atherosclerotic renovascular disease, renal artery stenting improves or stabilizes renal function and preserves kidney size.

Balloon aortic valvuloplasty revisited: the role of the inoue balloon and transseptal antegrade approach.

Percutaneous aortic balloon valvuloplasty (PABV) was developed to provide a less invasive alternative to aortic valve replacement. Despite initially favorable results, PABV has not produced reliable and durable outcomes. The Inoue balloon used for PABV via an antegrade transseptal approach may offer an improvement over the Mansfield balloons via the identical route. Thirteen consecutive patients with severe symptomatic aortic stenosis were referred for percutaneous aortic balloon valvuloplasty. All patients were considered unacceptably high-risk surgical candidates. Seven consecutive patients underwent antegrade transseptal PABV with Mansfield balloons and in the following six the Inoue balloon was used. The study group was characterized by advanced age (mean, 77) and multiple comorbid conditions (mean, 2.5/patient). Before PABV, the two groups did not differ with respect to age, mean NYHA class, LVEF, transaortic gradient, cardiac output, or aortic valve area. All patients had initial hemodynamic improvement. Complications included one stroke and one vascular injury. After valvuloplasty, cardiac output was not significantly changed. However, there was a significant decrease in aortic gradient and an increase in aortic valve area in both groups; the increase in aortic valve area was significantly greater in those treated with the Inoue balloon (P = 0. 039). Total follow-up mortality was high but appeared to be delayed in the Inoue group. The use of the Inoue balloon with an antegrade transseptal approach warrants further investigation as a preferred technique for PABV.

Angiographic and clinical outcomes following acute infarct angioplasty on saphenous vein grafts.

Acute infarct angioplasty on aortocoronary saphenous vein grafts (SVGs) poses significant challenges because of their degenerate morphology and presence of significant thrombus. Of 370 acute, primary, or rescue myocardial infarct angioplasties performed over 3 years, 21 (5.7%) were on SVGs in patients who had undergone previous coronary artery bypass grafting a mean of 7.2 years earlier. Mean duration of chest pain to start of intervention was 3.9 +/- 3.2 hours; 6 (29%) patients presented with cardiac shock and 4 had failed treatment with thrombolytic drugs. At intervention, 11 (52%) of the culprit SVGs were totally occluded. Flow was reestablished or improved in 18 (86%), but classified as Thrombolysis In Myocardial Infarction trial grade 3 in only 10 patients (48%). Distal embolization and "no reflow" occurred with a frequency of 57% and 71%, respectively. In-hospital mortality was 19%. At 6 months, freedom from death, repeat target vessel revascularization, or recurrent myocardial infarction was 55%. In 349 patients undergoing native vessel intervention, success and Thrombolysis In Myocardial Infarction trial 3 flow rates were seen in 95% and 73% of patients, respectively, and in-hospital mortality was 7.9%. This present study demonstrates that infarct angioplasty on culprit SVGs can be successful but is associated with higher rates of embolic complications and worse acute and long-term clinical outcomes compared with a parallel experience of acute infarct angioplasty on native coronary arteries.

Intimal tear without hematoma: an important variant of aortic dissection that can elude current imaging techniques.

BACKGROUND: The modern imaging techniques of transesophageal echocardiography, CT, and MRI are reported to have up to 100% sensitivity in detecting the classic class of aortic dissection; however, anecdotal reports of patient deaths from a missed diagnosis of subtle classes of variants are increasingly being noted. METHODS AND RESULTS: In a series of 181 consecutive patients who had ascending or aortic arch repairs, 9 patients (5%) had subtle aortic dissection not diagnosed preoperatively. All preoperative studies in patients with missed aortic dissection were reviewed in detail. All 9 patients (2 with Marfan syndrome, 1 with Takayasu's disease) with undiagnosed aortic dissection had undergone >/=3 imaging techniques, with the finding of ascending aortic dilatation (4.7 to 9 cm) in all 9 and significant aortic valve regurgitation in 7. In 6 patients, an eccentric ascending aortic bulge was present but not diagnostic of aortic dissection on aortography. At operation, aortic dissection tears were limited in extent and involved the intima without extensive undermining of the intima or an intimal "flap." Eight had composite valve grafts inserted, and all survived. Of the larger series of 181 patients, 98% (179 of 181) were 30-day survivors. CONCLUSIONS: In patients with suspected aortic dissection not proven by modern noninvasive imaging techniques, further study should be performed, including multiple views of the ascending aorta by aortography. If patients have an ascending aneurysm, particularly if eccentric on aortography and associated with aortic valve regurgitation, an urgent surgical repair should be considered, with excellent results expected.

Coronary-subclavian steal associated with severe aortic stenosis treated with combined percutaneous stenting and minimally invasive aortic valve replacement.

We describe coronary-subclavian steal restricting flow to the left internal mammary artery (LIMA) associated with critical aortic stenosis treated with combined percutaneous transluminal stenting and minimally invasive aortic valve replacement (AVR). An 86-year-old patient had coronary artery bypass graft placement (CABG) seven years prior with the LIMA anastomosed to the left anterior descending coronary artery (LAD). At the time of CABG, the patient had mild aortic stenosis and normal left ventricular function. By the time of re-presentation with refractory angina and heart failure, the patient had developed critical aortic stenosis. Because repeat CABG with median sternotomy risked damaging the LIMA, pre-operative revascularization was planned to minimize the likelihood of peri-operative ischemia. Stenting of the subclavian artery was performed prior to minimally invasive AVR.

Bilateral percutaneous balloon angioplasty of the axillary arteries in a patient with giant cell arteritis and upper extremity ischemic symptoms not responsive to corticosteroids.

Giant cell arteritis (GCA) is well known to present with protean manifestations. We describe a 68-year-old woman with persistent upper extremity ischemic symptoms despite adequate treatment for GCA. She underwent successful balloon angioplasty of bilateral axillary artery stenosis. To our knowledge this is the first case utilizing this technique in GCA. Our case highlights the rare but important circumstances under which interventional techniques both surgical and nonsurgical need to be considered in cases of GCA with arterial occlusion not responsive to corticosteroid therapy.

Extraction of fully deployed coronary stents.

Coronary stents are often used because of their potential to improve the acute and long-term results of balloon angioplasty. The Palmaz-Schatz stent has been approved for use by the U.S. Food and Drug Administration largely because of a demonstrated reduction in the incidence of restenosis following its primary implantation. The Gianturco-Roubin design has been approved for use when balloon angioplasty results in threatened or acute vessel closure. In practice, both stent types are being used in settings when the results of balloon angioplasty are either potentially or actually unacceptable. In such circumstances it is imperative that stents be placed accurately and carefully. Occasionally, stent misplacement, embolization, or disruption can occur, and the need arises to recover and/or reposition the wayward prosthesis. This review describes the removal and recovery of fully deployed Gianturco-Roubin stents using an intracoronary snare technique.

The management of mitral valve disease.

Clinical investigators continue to make significant advancements in the diagnosis and treatment of patients with mitral valve disease. The salutary effects of mitral balloon valvotomy for mitral stenosis and the development of a reasonable approach to the asymptomatic patient with chronic mitral regurgitation are examples of relevant research that affects clinical outcomes. Recent developments in the management of patients with mitral valve disease are reviewed.

Comparison of percutaneous transluminal coronary angioplasty outcome and hospital costs for low-volume and high-volume operators.

Whether higher operator case volume is associated with improved percutaneous transluminal coronary angioplasty (PTCA) clinical and cost outcomes is the subject of this study. Hospital volume-related improvement in clinical outcomes has been shown for coronary artery bypass grafting (CABG) and PTCA. Physician case volume-related differences in clinical outcomes have not been clearly demonstrated, and differences in hospital costs have not been examined. For clinical and cost outcomes, risk-adjusted analysis of differences in PTCA outcomes has not been reported. In addition, controversy exists about the appropriate annual case volume considered adequate to maintain skills and achieve optimal clinical outcomes in performing PTCA procedures. We studied 2,350 PTCAs performed between March 1, 1991, and February 28, 1994. Physicians were divided into 2 volume groups: high (>50 cases/year) and low (<50 cases/year). The rate of emergency CABG after PTCA was 2.1% for high- and 3.9% for low-volume operators (p = 0.009). Hospital morbidity associated with PTCA was lower in high-than in low-volume operators (6.46% vs 10.73%, p <0.001). The risk-adjusted ratios for emergency CABG and morbidity were 2.05 (p = 0.005) and 1.79 (p <0.001), respectively. The length of stay averaged 4.07 +/- 4.54 days for high- and 4.49 +/- 4.33 days for low-volume operators (p = 0.003). Hospital costs averaged $7,977 +/-$7,269 for high- and $8,278 +/- $6,289 for low-volume operators (p = 0.065). The risk adjusted ratio was 1.091 (p = 0.004) for length of stay and 1.050 (p = 0.029) for cost. Thus, PTCA performed by high-volume operators is significantly less likely to require emergency CABG and is also significantly associated with lower hospital morbidity, shorter hospital length of stay, and lower hospital costs.

Sequential directional atherectomy of coronary bifurcation lesions.

Conventional techniques of coronary angioplasty for lesions at coronary bifurcations are well documented, are sometimes cumbersome, and have inherent limitations. We describe a technique for sequential atherectomy at coronary bifurcations. Further evaluation is needed to determine the overall safety, efficacy, applicability and durability of sequential directional atherectomy at coronary bifurcations.

Late direct angioplasty in patients with myocardial infarction and fluctuating chest pain.

Myocardial infarctions may be associated with reduced but persistent blood flow to the infarct zone. We developed clinical criteria to select patients likely to have persistent perfusion to the infarct zone in the setting of acute myocardial infarction. Twenty-four consecutive patients with fluctuating pain and/or ST segment elevation who presented within 24 hours of the onset of infarction were studied with coronary angiography followed by direct percutaneous transluminal coronary angioplasty. Sixty-seven percent of patients had residual flow to the infarct territory. Eighteen patients had repeat angiography on day 9.4 +/- 4.1, and all arteries were patent (21% +/- 12% stenosis). Ejection fraction had risen from 50.0% +/- 15% to 54.0% +/- 14% (p less than 0.05). At follow-up (9.1 +/- 4.6 months), one patient died of noncardiac causes, and five redeveloped angina and underwent repeat procedures. Patients with fluctuating symptoms and/or ST segments are likely to have residual flow to the infarct zone, and late angioplasty may improve ventricular function in this group.

Nifedipine protects the heart from the acute deleterious effects of cocaine if administered before but not after cocaine.

BACKGROUND: We tested the hypothesis that nifedipine, a calcium channel blocker, could ameliorate the toxic effects of cocaine on the myocardium. METHODS AND RESULTS: In an initial protocol, anesthetized dogs were pretreated with nifedipine or saline and then administered cocaine (10 mg/kg, i.v. bolus). Coronary blood flow, heart rate, mean arterial pressure, and the first derivation of left ventricular pressure (dP/dt) were measured at baseline, 2 minutes, and 15 minutes after cocaine administration. Nifedipine pretreatment prevented the early cocaine-induced decrease in coronary blood flow and improved left ventricular dP/dt compared with untreated control animals. After cocaine, ejection fraction fell in the saline group to 37 +/- 3% but increased in the nifedipine group to 59 +/- 4% (p less than 0.05). In a second protocol, vehicle or intravenous nifedipine was administered after an infusion of cocaine (10 mg/kg). In contrast to pretreatment, there was no significant improvement in left ventricular function or coronary blood flow in nifedipine-treated versus control animals. Data from the study also suggested that cocaine acts directly on the myocardium. Within seconds of cocaine bolus administration, coronary blood flow in control animals increased to a peak level 59 +/- 14% higher than before cocaine and left ventricular dP/dt decreased by 23 +/- 5%, providing evidence that cocaine causes direct depression of myocardial function independent of a decrease in myocardial blood flow. CONCLUSIONS: We conclude that nifedipine administered as a pretreatment protects against the depression of myocardial function and decrease in coronary blood flow caused by acute cocaine administration. However, when nifedipine is given after cocaine, no improvement is seen. Cocaine has a direct negative inotropic effect on the heart that is independent of a decrease in coronary blood flow.

The effect of balloon angioplasty on vasa vasorum blood flow in canine coronary arteries.

To assess the effects of balloon dilatation on vasa vasorum flow, we performed percutaneous transluminal coronary angioplasty on the circumflex arteries of 12 dogs. Left anterior descending and circumflex coronary vasa vasorum flows were measured with radioactive microspheres at baseline, during, and 10 minutes after a 3-minute, 8 atm balloon inflation. With inflation, vasa vasorum flow at the balloon dilatation site profoundly decreased (from 0.25 +/- 0.08 to 0.03 +/- 0.01 ml/min/gm). The flow returned to normal within 10 minutes after deflation. This effect was not mediated by hemodynamic deterioration during coronary occlusion and did not occur in the contralateral coronary artery. Endomyocardial flow in the distribution of the dilated artery decreased markedly during balloon inflation (from 1.14 +/- 1.9 to 0.08 +/- 0.04 ml/min/gm), which confirmed coronary occlusion. We conclude that a prolonged decrease in vasa vasorum flow is not produced by experimental balloon angioplasty, which makes it unlikely that a sustained vasa vasorum flow reduction plays a role in the maintenance of patency or the induction of restenosis.

Pacemaker-mediated tachycardias: an unresolved problem.

The advent of dual chamber pacing systems that restore atrioventricular synchrony and allow rate variability in response to physiologic stress has provided a major advance in pacing therapy. Undesirable pacemaker-mediated tachycardias may arise when the atrial sensing amplifier of a VDD or DDD device detects a retrogradely conducted P-wave, ectopic atrial tachycardia, myopectoral contractions, or environmental electromagnetic interference. The rate of the resultant tachycardia is determined by the programmed upper tracking rate of the pacemaker. Although seldom life-threatening, troublesome myocardial ischemia may ensue in patients with coronary artery disease. In most instances, the incidence and rate of pacemaker-mediated tachycardias may be minimized by judicious programming.