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Biomedical subjects

Gregg C Fonarow

Publications and source records attributed to Gregg C Fonarow.

At least 91 records · Page 5Linked to original sources
PubMed2004

Azygos vein lead implantation: a novel adjunctive technique for implantable cardioverter defibrillator placement.

High defibrillation thresholds (DFTs) occasionally are encountered during placement of implantable cardioverter defibrillators (ICDs). There are multiple strategies to lower DFTs in such patients, including reassessment of right ventricular lead position, alteration of the shock waveform, and implantation of subcutaneous arrays. This article describes a novel technique of implanting a high-voltage lead in the azygos vein. This procedure may serve as an adjunctive approach to reduce DFTs. The anatomic location of the azygos vein posterior to the heart provides a suitable shocking vector between the right ventricular electrode, a high-voltage lead placed in the azygos vein, and the ICD can.

Adult↗
PubMed2004

Muscle mechanoreceptor sensitivity in heart failure.

Prior work in animals suggests that muscle mechanoreceptor control of sympathetic activation (MSNA) during exercise in heart failure (HF) is heightened and that muscle mechanoreceptors are sensitized by metabolic by-products. We sought to determine whether 1) muscle mechanoreceptor control of MSNA is enhanced in HF patients and 2) lactic acid sensitizes muscle mechanoreceptors during rhythmic handgrip (RHG) exercise in healthy humans and patients with HF. Dichloroacetate (DCA), which reduces the production of lactic acid, or saline control was infused in 12 patients with HF and 13 controls during RHG. MSNA was recorded (microneurography). After saline was administered and during exercise thereafter, MSNA increased earlier in HF compared with controls, consistent with baseline-heightened mechanoreceptor sensitivity. In both HF and controls, MSNA increased during the 3-min exercise protocol, consistent with further sensitization of muscle mechanoreceptors by metabolic by-product(s). During posthandgrip circulatory arrest, MSNA returned rapidly to baseline levels, excluding the muscle metaboreceptors as mediators of the sympathetic excitation during RHG. To isolate muscle mechanoreceptors from central command, we utilized passive exercise in 8 HF and 11 controls, and MSNA was recorded. MSNA increased significantly during passive exercise in HF but not in controls. In conclusion, muscle mechanoreceptors mediate the increase in MSNA during low-level RHG exercise in healthy humans, and this muscle mechanoreceptor control is augmented further in HF. Neither lactate generation nor the fall in pH during RHG plays a central role in muscle mechanoreceptor sensitization. Finally, muscle mechanoreceptors in patients with HF have heightened basal sensitivity to mechanical stimuli resulting in exaggerated early increases in MSNA.

Arm↗
PubMed2004

Strategies to improve the use of evidence-based heart failure therapies: OPTIMIZE-HF.

Patients with heart failure face a very high risk of hospitalizations and mortality. Despite the compelling scientific evidence that angiotensin-converting enzyme inhibitors, beta-blockers, and aldosterone antagonists reduce hospitalizations and mortality in patients with heart failure, these life-saving therapies continue to be underutilized. A number of studies in a variety of clinical settings have documented that a significant proportion of patients with heart failure are not receiving treatment with these guideline-recommended, evidence-based therapies when guided by conventional care. Treatment gaps in providing other components of heart failure patient care, including patient education, have also been documented. The demonstration that initiation of cardiovascular protective medications prior to hospital discharge results in a marked increase in treatment rates, improved long-term patient compliance, and better clinical outcomes has led to the revision of national guidelines to endorse this approach as the standard of care. Recent studies demonstrated that beta-blocker therapy can be safely and effectively initiated in heart failure patients prior to hospital discharge, resulting in improved treatment rates and clinical outcomes. The Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) is a national collaborative designed to improve medical care and education of hospitalized heart failure patients and to accelerate initiation of evidence-based heart failure guideline-recommended therapies by administering them before hospital discharge. A registry focusing on hospital admission to discharge and 60-90 day follow-up is designed to evaluate the demographic, pathophysiologic, clinical, treatment, and outcome characteristics of patients hospitalized with heart failure. The aim of this program is to improve the standard of heart failure care in the hospital and outpatient settings and to increase the use of evidence-based therapeutic strategies to prolong life in the large number of heart failure patients hospitalized each year.

Adrenergic beta-Antagonists↗
PubMed2003

Cardiac troponin I is associated with impaired hemodynamics, progressive left ventricular dysfunction, and increased mortality rates in advanced heart failure.

BACKGROUND: Cardiac troponin I (cTnI), a sensitive and specific marker of myocardial cell injury, is useful in diagnosing and assessing prognosis in acute coronary syndromes. Small studies report that cTnI is elevated in severe heart failure (HF) and may predict adverse outcomes. METHODS AND RESULTS: The present study evaluated 238 patients with advanced HF referred for cardiac transplantation evaluation who had cTnI assay drawn at the time of initial presentation. Patients with acute myocardial infarction or myocarditis were excluded from analysis. cTnI was detectable (cTnI > or =0.04 ng/mL) in serum of 117 patients (49.1%). Patients with detectable cTnI levels had significantly higher B-type natriuretic peptide (BNP) levels (P<0.001) and more impaired hemodynamic profiles, including higher pulmonary wedge pressures (P=0.002) and lower cardiac indexes (P<0.0001). A significant correlation was found between detectable cTnI and progressive decline in ejection fraction over time. Furthermore, detectable cTnI was associated with increased mortality risk (RR, 2.05; 95% CI, 1.22 to 3.43). After adjustment for other factors associated with adverse prognosis including age, sex, ejection fraction, and coronary artery disease, cTnI remained a significant predictor of death. cTnI used in conjunction with BNP further improved prognostic value. CONCLUSIONS: cTnI is associated with impaired hemodynamics, elevated BNP levels, and progressive left ventricular dysfunction in patients with HF. cTnI may be a novel, useful tool in identifying patients with HF who are at increased risk for progressive ventricular dysfunction and death.

Academic Medical Centers↗
PubMed2003

Effective strategies for long-term statin use.

Long-term statin use achieves a significant reduction in mortality (24% to 42%) for patients with coronary artery disease (CAD) that is equal to or greater than that seen with other secondary prevention medications, including aspirin, beta-blockers, and angiotensin-converting enzyme (ACE) inhibitors. In patients with diabetes, the reduction in mortality exceeds that seen with tight glycemic control or any other treatment for diabetes. Several studies have found that almost all patients with atherosclerosis are considered candidates for statin treatment. The scientific evidence needed to revise the national guidelines has been provided by showing that initiation of statins before hospital discharge results in (1). a marked increase in long-term treatment rates, (2). improved long-term patient compliance, (3). more patients reaching levels of low-density lipoprotein (LDL) cholesterol <100 mg/dL, and (4). improved clinical outcome. Nonetheless, many studies in a variety of clinical settings have demonstrated that, regardless of the health care delivery system, an unacceptable number of patients with atherosclerosis are left untreated or undertreated with statin therapy. Applying hospital-based systems has been demonstrated to address the problems of underuse. The national guidelines now recommend that, in addition to diet and exercise counseling, lipid-lowering medications be initiated before hospital discharge for patients diagnosed with cardiovascular disease. Optimal use of statins and other cardioprotective medications in high-risk patients could save >83000 lives per year in the United States.

Cardiovascular Diseases↗
PubMed2003

Efficacy of angiotensin-converting enzyme inhibitors and beta-blockers in the management of left ventricular systolic dysfunction according to race, gender, and diabetic status: a meta-analysis of major clinical trials.

OBJECTIVES: This study sought to assess the effect of angiotensin-converting enzyme (ACE) inhibitors and beta-blockers on all-cause mortality in patients with left ventricular (LV) systolic dysfunction according to gender, race, and the presence of diabetes. BACKGROUND: Major randomized clinical trials have established that ACE inhibitors and beta-blockers have life-saving benefits in patients with LV systolic dysfunction. Most patients enrolled in these trials were Caucasian men. Whether an equal effect is achieved in women, non-Caucasians, and patients with major comorbidities has not been established. METHODS: The authors performed a meta-analysis of published and individual patient data from the 12 largest randomized clinical trials of ACE inhibitors and beta-blockers to produce random effects estimates of mortality for subgroups. RESULTS: Data support beneficial reductions in all-cause mortality for the use of beta-blockers in men and women, the use of ACE inhibitors and some beta-blockers in black and white patients, and the use of ACE inhibitors and beta-blockers in patients with or without diabetes. Women with symptomatic LV systolic dysfunction probably benefit from ACE inhibitors, but women with asymptomatic LV systolic dysfunction may not have reduced mortality when treated with ACE inhibitors (pooled relative risk = 0.96; 95% confidence interval: 0.75 to 1.22). The pooled estimate of three beta-blocker studies supports a beneficial effect in black patients with heart failure, but one study assessing bucindolol reported a nonsignificant increase in mortality. CONCLUSIONS: Angiotensin-converting enzyme inhibitors and beta-blockers provide life-saving benefits in most of the subpopulations assessed. Women with asymptomatic LV systolic dysfunction may not achieve a mortality benefit when treated with ACE inhibitors.

Adrenergic beta-Antagonists↗
PubMed2003

Regional brain gray matter loss in heart failure.

Heart failure (HF) patients exhibit enhanced sympathetic tone, aberrant responses to blood pressure challenges, and sleep-related breathing disorders, suggesting that the syndrome is accompanied by central neural deficits. We assessed regional gray matter volumes over the entire brain in nine HF patients (51 +/- 10 yr; left ventricular ejection fraction 0.27 +/- 0.06; six men) and 27 healthy controls (46 +/- 12 yr; 22 men) using T1-weighted magnetic resonance imaging to evaluate potential neural damage. Regional volumes were evaluated by using voxel-based morphometry while controlling for age, gender, and handedness. HF patients showed significant and largely lateralized gray matter loss in autonomic and respiratory-related areas as well as regions not classically associated with such control, including the insula and basal ganglia, right cingulate gyrus, parahippocampal/fusiform gyrus, dorsal midbrain extending to the posterior and medial thalamus, ventral and superior lateral frontal cortex, bilateral cerebellar quadrangular lobules and right fastigial and neighboring nuclei, and bilateral deep parietal and lateral parietal-occipital cortex. Areas of gray matter loss may contribute to inappropriate cognitive, autonomic, and breathing regulation in HF.

Adult↗
PubMed2003

Lessons learned from recent lipid-lowering trials: why physicians should change clinical practice.

In the past decade there has been an explosion of data on the beneficial role of cholesterol reduction in the prevention and treatment of cardiovascular disease (CVD). While earlier clinical trials focused primarily on patient populations with very high cholesterol levels, more recent studies have also included individuals with somewhat lower, or "average," cholesterol levels. What is becoming clearer is that many patients with so-called "average" cholesterol levels may benefit from cholesterol reduction therapy to reduce the risk of cardiovascular events. Recent studies, such as the Heart Protection Study, provide further evidence for cholesterol reduction in the prevention and treatment of CVD and offer valuable lessons about cardiovascular risk reduction.

Adult↗
PubMed2003

B-type natriuretic peptide: spectrum of application. Nesiritide (recombinant BNP) for heart failure.

The therapeutic goals for patients hospitalized with acutely decompensated heart failure are to reverse acute hemodynamic abnormalities, relieve symptoms, and to initiate heart failure therapies which will decrease disease progression and improve long-term survival. Nesiritide (recombinant B-type natriuretic peptide) is the first in a new class of therapeutic agents for the treatment of heart failure and has been demonstrated to offer a unique combination of safety and efficacy. The use of nesiritide on top of standard care including diuretic therapy, has been proven to lead to meaningful clinical benefits in a broad range of acutely decompensated heart failure patients. Nesiritide is an attractive therapeutic option because of its more rapid and sustained hemodynamic profile, more favorable effects on neurohormonal suppression, with less adverse effects than alternative intravenous heart failure treatments such as nitroglycerine, nitroprusside, dobutamine, or milrinone. The use of nesiritide is the most effective initial treatment approach among currently available strategies to reverse acutely decompensated heart failure and to facilitate optimization of the heart failure medical regimen.

Acute Disease↗
PubMed2003

Use of two recipient lists for adults requiring heart transplantation.

OBJECTIVE: An alternate (second) adult recipient list was used to match excluded potential recipients with nonstandard donor hearts that would otherwise be unused. METHODS: The only absolute criterion for entering the alternate recipient list was age: 65 years old before 1998 and 70 years old after that. Group I consisted of alternates who underwent transplantation, and group II consisted of 401 contemporaneous recipients. Hearts were first offered to regularly listed patients. At least one of the following donor risks accounted for allocation to an alternate: coronary artery disease, reused transplanted heart, high-risk behavior, hepatitis seropositivity, decreased left ventricular ejection fraction, high inotropic requirement, left ventricular hypertrophy, age older than 55 years plus another risk, and small donor with no other matches. RESULTS: Of 102 alternates, 82 were listed were because of age. After a median wait of 107 days, 62 alternates underwent transplantation. Median alternate recipient age was 67 years (vs 54 years, P <.001). Median donor age was 45 years (vs 31 years, P <.001). Survival for alternates at 90 days was 82% (vs 91%, P =.04). Significant recipient predictors of early mortality on multivariable analysis (n = 463) were previous cardiac surgery (odds ratio 2.74, 95% confidence interval 1.37-5.48) and renal dysfunction (odds ratio 1.39, 1.10-176). Alternate listing did not independently predict early or late mortality. Late (>90 days) death rates per 1000 person-months were 4.3 and 3.6 for groups I and II (relative risk 1.2, 0.62-2.36). CONCLUSIONS: Use of two adult recipient lists facilitated allocation of unused donor organs. Satisfactory long-term survival supports the use of an alternate recipient list.

Adult↗
PubMed2003

Aggressive treatment of atherosclerosis: the time is now.

In patients with known cardiovascular disease and those at high risk for it, physicians must begin to treat atherosclerosis earlier, with combination therapy of statins, aspirin, angiotensin-converting enzyme inhibitors, and beta-blockers. In those hospitalized with a cardiovascular event, a statin should be started in the hospital, regardless of lipid levels. Patients with diabetes should be treated as if they have preexisting cardiovascular disease.

Aspirin↗
PubMed2003

Support with the BVS 5000 assist device during treatment of acute giant-cell myocarditis.

Giant-cell myocarditis is a rare and aggressive form of myocarditis with a high mortality rate. Our purpose is to summarize 3 cases of acute giant-cell myocarditis that illustrate possible outcomes with mechanical support. We reviewed the cases of 3 patients, aged 39 to 59 years, who had giant-cell myocarditis (confirmed by myocardial biopsy). The indication for ventricular assist was circulatory failure despite maximal medical treatment with 2 or more inotropic agents and intraaortic balloon pump support. Immunosuppression and a biventricular mechanical assist (BVS 5000) were used to treat all these patients. The mean duration of mechanical support was 15.7 days (range, 10 to 19 days). One patient had recovery of myocardial function and was weaned from mechanical support. This case is, to our knowledge, the first reported of ventricular support leading to cardiac recovery after diagnosis of giant-cell myocarditis. The 2nd patient was not a candidate for further surgery and died of multisystem organ failure. The 3rd patient underwent orthotopic heart transplantation after 18 days of support and was discharged. We conclude that patients with giant-cell myocarditis tend to have biventricular involvement and can recover myocardial function on mechanical support and immunosuppression. If recovery is not observed, transplantation is warranted. By avoiding left ventricular cannulation, the BVS 5000 is well suited for bridging to recovery, transplantation, or long-term support.

Acute Disease↗