Effects of selective alpha1- and alpha2-adrenergic blockade on coronary flow reserve after coronary stenting.

BACKGROUND: Coronary flow reserve (CFR) is not normalized shortly after coronary stenting. We hypothesized that alpha-adrenergic coronary vasoconstriction acts to limit CFR. METHODS AND RESULTS: We assessed flow velocity by Doppler wires and cross-sectional area by angiography in 46 patients undergoing coronary culprit lesion stenting (81+/-4% stenosis). Hyperemia was induced by adenosine (24 micro g IC or 140 micro g/kg per minute IV) before and after stenting. Finally, either the alpha(1)-antagonist urapidil (10 mg IC) or the alpha(2)-antagonist yohimbine (3 mg IC) was randomly combined with adenosine. In 8 subjects with angiographically normal coronary arteries, CFR was increased from 3.21+/-0.30 to 3.74+/-0.43 by yohimbine and to 4.58+/-0.65 by urapidil, respectively (P=0.0001). Patients were divided according to the cutoff of CFR > or =3.0 (n=18) or <2.5 (n=28). Revascularization per se did not change CFR. However, 15 minutes after stenting, CFR decreased to 2.05+/-0.55 from CFR 3.64+/-0.58, whereas in patients with CFR 2.39+/-0.51, it remained unchanged. Yohimbine improved CFR to 3.26+/-0.42 and to 3.41+/-0.58 in patients with >3.0 and <2.05+/-0.55 baseline CFR, respectively. Urapidil improved CFR to 3.52+/-0.30 and 3.98+/-1.07, respectively. CONCLUSIONS: Urapidil and yohimbine attenuated the CFR impairment occurring after revascularization by increasing both the epicardial vasodilator effect of adenosine and the blood flow velocity, thus suggesting that the adrenergic system plays an important role in limiting the capacity of the coronary circulation to dilate.

Posterior mitral valve restoration for ischemic regurgitation.

Chronic ischemic mitral regurgitation is traditionally a complex lesion to repair. Only restrictive annuloplasty has become an accepted strategy to avoid valve replacement, but results are unsatisfactory in some subgroups of patients. We describe an original technique that addresses the pathophysiologic mechanisms responsible for one of the most common subtypes of ischemic mitral regurgitation, ie, asymmetric tethering of the mitral leaflets after inferior myocardial infarction. The technique includes partial detachment of the posterior leaflet from the mitral annulus, annular plication, and posterior cusp plasty.

Early surgical anteroseptal ventricular endocardial restoration after acute myocardial infarction. Pathophysiology and surgical considerations.

BACKGROUND: The efficacy and safety of surgical anteroseptal ventricular endocardial restoration (a procedure that excludes non-contracting scarred segments) in the left ventricle with chronic dilation and remodeling secondary to an anterior myocardial infarction are well established. We present a small series and discuss the indication for early left ventricular restoration in the setting of complicated acute myocardial infarction. METHODS: Early ventricular restoration was performed in 8 patients (4 males, 4 females, mean age 70 +/- 8 years). A postinfarction ventricular septal defect was diagnosed in 3 cases. All patients were operated, on an urgent or emergent basis, between 1 and 16 days following the onset of infarction. Surgical coronary revascularization was associated in 7 patients. RESULTS: There was one operative death. At discharge, echocardiographic morphofunctional assessment revealed: a reduction of the left ventricular end-diastolic and end-systolic volume indexes, an increase of the ejection fraction, and, most importantly, an improvement of remote myocardial shortening fraction. At a mean follow-up of 15.6 months (range 2-21 months), there were no late deaths and all survivors are in NYHA functional class I or II. CONCLUSIONS: Left ventricular restoration may represent an effective adjunct to the surgical management of patients with an acute extensive anterior myocardial infarction complicated by severe heart failure, with or without septal rupture.

Coronary artery bypass for heart failure in ischemic cardiomyopathy: 17-year follow-up.

BACKGROUND: Coronary artery bypass grafting (CABG) has been safely extended to ischemic cardiomyopathy and heart failure, but outcome beyond 5 years remains poorly defined. METHODS: We retrospectively analyzed 45 consecutive angina-free patients with ischemic left ventricular dysfunction (ejection fraction < or = 0.35) and heart failure (New York Heart Association functional class III to IV) who were selected for CABG between 1988 and 1995. Positron emission tomography was used for preoperative identification of myocardial viability. RESULTS: The 30-day mortality was 4.4%. At a median follow-up of 117 months (longest observation, 205 months), the probability of survival at 1, 5, 10, and 15 years after CABG was 93.3%, 84%, 65%, and 44%, respectively. At multivariable analysis, a left ventricular end-diastolic pressure (LVEDP) of 25 mm Hg or more predicted a threefold increase of the hazard of death (p = 0.02), whereas a LVEDP of 20 mm Hg or more correlated with the requirement of an intraaortic balloon pump perioperatively (p = 0.04). Other independent predictors of survival were age older than 70 years and peripheral vascular disease. Cardiac events accounted for 88% of late deaths, which were primarily related to sudden death or progressive heart failure. Most patients were in New York Heart Association functional class I to II at late follow-up. CONCLUSIONS: CABG alone yields good long-term outcome in selected angina-free patients with ischemic systolic dysfunction and advanced heart failure. However, associated diastolic impairment, reflected by elevated LVEDP, predicts reduced long-term survival despite myocardial viability.

Spinal cord retrograde perfusion: review of the literature and experimental observations.

BACKGROUND: Spinal cord damage represents a devastating complication of thoracic and thoracoabdominal aortic surgery. Retrograde perfusion as an alternative route to protect the spinal cord has recently been investigated with controversial results. We reviewed the literature and analyzed additional experimental observations. METHODS: Ten juvenile pigs were divided into control and study groups (A and B, respectively). Through a lateral thoracotomy the distal aortic arch was cannulated and connected to a cardiotomy reservoir. All animals underwent 40-minute single cross-clamping of the proximal descending aorta while keeping proximal systolic arterial pressure above 100 mmHg. In group B, normothermic arterial blood was delivered retrogradely through the azygos vein, maintaining perfusion pressure within 25-30 mmHg. Animals were allowed to recover to perform a primary neurologic evaluation. RESULTS: Flaccid paraplegia was uniformly observed in group A. In group B, all animals showed mild-to-moderate voluntary hind limb movements on awakening (p = 0.007). Controls also showed urine incontinence short after cross-clamping, and this was not observed in group B (p = 0.008). A different veno-arterial oxygen step-down was observed in blood collected from the excluded aorta in the two groups (p < 0.001). CONCLUSIONS: Preliminary results indicate that controlled retrograde normothermic perfusion alone through the azygos system provides some degree of protection from spinal cord ischemia. Bladder dysfunction may represent a simple test to detect massive cord damage intraoperatively. Retrograde spinal cord perfusion warrants further investigation.