Prevalence and determinants of valvulopathy in patients treated with dexfenfluramine

Targeting the 5-HT system: Potential side effects

Targeting the serotonin (5-HT) system is no simple task: there are at least 15 5-HT receptors, in addition to a number of transporters and metabolizing enzymes. Multiple 5-HT receptor variants exist due to genetic variations and/or post translational modifications, splice variants or editing variants. Some receptors may form homo and heteromers. The 5-HT system is targeted by multiple drugs to treat a variety of diseases. Given the homology amongst the 5-HT and neighbouring receptor classes, only few drugs are actually selective for a single target. In fact, many 5-HT drugs act on a combination of targets, i.e. several receptors and/or transporters or enzymes. For instance, a number of antidepressants or antipsychotics act on 5-HT and other transmitter systems. Recently developed drugs may show target selectivity by design, based on the current state of knowledge, whereas many older compounds hit multiple targets since they were developed using phenotypic screens, as was done well into the 1980's. Ergot analogues, antipsychotics or antidepressants, fall into this category. As our knowledge developed over the last 25-30 years, some targets have very well-defined liabilities: for instance, 5HT_2B or 5-HT_2A receptor agonists, will produce valvulopathies or hallucinations, respectively, whereas 5-HT₃ receptor antagonists, may lead to constipation. This short review will be limited in scope as there are multiple targets and even more compounds to discuss. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.

Cardiovascular safety of low-dose fenfluramine in Dravet syndrome: a review of its benefit-risk profile in a new patient population

OBJECTIVE

Dravet syndrome (DS) is a rare, treatment-resistant epilepsy syndrome for which current treatment regimens are often ineffective. Fenfluramine is currently in development for treatment of DS, based on reports in the 1980s and 1990s of its anti-epileptic activity in pediatric patients with intractable epilepsy. However, fenfluramine was withdrawn from global markets in 1997 following reports of its association with pulmonary hypertension and heart valve disease in adult patients treated for obesity. This review was conducted to assess cardiac safety of fenfluramine when used at lower doses for treatment of DS.

METHODS

Pubmed was searched for clinical studies of fenfluramine in obese adults who reported incidence of heart valve disease. These data were reviewed against published results from Belgian patients with DS who have been treated with low-dose fenfluramine for up to 28 years.

RESULTS

Nine controlled studies of fenfluramine and related compounds (dexfenfluramine and/or phentermine) which assessed incidence and severity of cardiac valve disease in 3,268 treated patients and 2,017 control subjects have been reported. Mild or greater aortic valve regurgitation was found in 9.6% of treated patients compared with 3.9% of control subjects, and moderate or greater mitral valve regurgitation was found in 3.1% of treated patients and 2.5% of control subjects. Nineteen DS patients have been treated for up to 28 years with 10-20 mg/day fenfluramine, with no clinical signs or symptoms of cardiac valve disease or pulmonary hypertension. Slight and clinically unimportant changes in valve structure have been seen on echocardiography in five patients at some time during the observation period.

CONCLUSIONS

A different benefit-risk relationship appears to be emerging when fenfluramine is used at low doses for extended periods in young patients with DS. Continued cardiac assessments during ongoing Phase 3 clinical trials will provide additional safety information for this potential new and effective treatment.

Reverse translation of adverse event reports paves the way for de-risking preclinical off-targets

The Food and Drug Administration Adverse Event Reporting System (FAERS) remains the primary source for post-marketing pharmacovigilance. The system is largely un-curated, unstandardized, and lacks a method for linking drugs to the chemical structures of their active ingredients, increasing noise and artefactual trends. To address these problems, we mapped drugs to their ingredients and used natural language processing to classify and correlate drug events. Our analysis exposed key idiosyncrasies in FAERS, for example reports of thalidomide causing a deadly ADR when used against myeloma, a likely result of the disease itself; multiplications of the same report, unjustifiably increasing its importance; correlation of reported ADRs with public events, regulatory announcements, and with publications. Comparing the pharmacological, pharmacokinetic, and clinical ADR profiles of methylphenidate, aripiprazole, and risperidone, and of kinase drugs targeting the VEGF receptor, demonstrates how underlying molecular mechanisms can emerge from ADR co-analysis. The precautions and methods we describe may enable investigators to avoid confounding chemistry-based associations and reporting biases in FAERS, and illustrate how comparative analysis of ADRs can reveal underlying mechanisms.

DOI:http://dx.doi.org/10.7554/eLife.25818.001

New treatments are tested in clinical trials before they are licensed for use in patients, but until the drugs are available for prescribing it’s not always possible to identify every side effect. When the drugs enter the clinic, they might be prescribed to patients with multiple medical conditions, or combined with other treatments. The drugs may also be taken for longer periods of time than tested in trials. It is therefore common for new adverse reactions to emerge after a drug is in widespread use.

The FDA Adverse Event Reporting System (FAERS) is a surveillance system used in the United States for reporting drug side effects after new treatments have been licensed. Healthcare professionals and patients can submit reports to the database, logging the adverse drug reactions that they have experienced.

FAERS currently contains over 8.5 million entries, and is growing all the time. However, Maciejewski et al. show that the database has several shortcomings that are reducing its usefulness. For instance, on average any given drug will have 16 different names in the system; this makes it challenging to group all of the reported side effects so that trends and patterns can be correctly seen.

To address this first problem, Maciejewski et al. grouped together drugs according to their active ingredients, rather than their name. This made it much easier to account for subsequent, and more crucial conflating factors such as multiple reports for the same adverse event and patient, or cases where adverse reactions were confused with the diseases that the drugs are trying to treat. For example, diabetes was listed as a side effect for drugs used to treat diabetes.

Building on this cleaned-up dataset, Maciejewski et al. monitored how adverse event signals evolve over time and uncovered biases that were hard to see otherwise. For example, side-effects were reported more often when drugs were in the news. More strikingly, this bias affected not only the drug in question, but also other drugs that acted in the same way or on the same molecular target.

The computational method developed by Maciejewski et al. allows the data in FAERS to be combined and corrected, making easier to evaluate the safety of different medicines. The link between adverse side effects and the molecular targets of the drug, via the ingredient’s chemical structure, furthermore makes it possible to analyze such clinical data reliably by using chemical and genetic information. In the future, this method could also help to identify previously unknown side effects and the biological mechanisms behind them. This could help researchers to develop new drugs with improved side effect profiles.

DOI:http://dx.doi.org/10.7554/eLife.25818.002

Effects of lorcaserin on pre-existing valvulopathy: A pooled analysis of phase 3 trials

OBJECTIVE

To evaluate the effects of lorcaserin in patients with pre-existing Food and Drug Administration (FDA)-defined valvulopathy.

METHODS

This is a pooled, post hoc analysis of three Phase 3 studies. BLOOM and BLOSSOM patients were 18 to 65 years of age without diabetes and with a body mass index (BMI) of 27 to 29.9 kg/m² and ≥1 weight-related comorbidity or a BMI of 30 to 45 kg/m² . BLOOM-DM patients had a BMI of 27 to 45 kg/m² and type 2 diabetes. Patients were treated with placebo, lorcaserin 10 mg once daily, or lorcaserin 10 mg twice daily. Serial echocardiographs were obtained at baseline and every 6 months.

RESULTS

Included patients (N = 169) had FDA-defined valvulopathy at baseline and a week 52 echocardiogram. At week 52, 35.5% and 52.7% of patients experienced changes from baseline in aortic and mitral regurgitation, respectively. Numerically greater proportions of patients taking lorcaserin versus placebo had decreases in aortic (33.0% vs. 28.3%) or mitral (41.3% vs. 36.7%) regurgitation. Fewer patients taking lorcaserin versus placebo had increases in aortic (2.8% vs. 6.7%) or mitral (8.3% vs. 21.7%) regurgitation. No adverse event-related discontinuation was due to a valve problem.

CONCLUSIONS

These data suggest that lorcaserin does not adversely affect valvular disease in patients with pre-existing FDA-defined valvulopathy.

Developmental basis for filamin-A-associated myxomatous mitral valve disease

AIMS

We hypothesized that the structure and function of the mature valves is largely dependent upon how these tissues are built during development, and defects in how the valves are built can lead to the pathological progression of a disease phenotype. Thus, we sought to uncover potential developmental origins and mechanistic underpinnings causal to myxomatous mitral valve disease. We focus on how filamin-A, a cytoskeletal binding protein with strong links to human myxomatous valve disease, can function as a regulatory interface to control proper mitral valve development.

METHODS AND RESULTS

Filamin-A-deficient mice exhibit abnormally enlarged mitral valves during foetal life, which progresses to a myxomatous phenotype by 2 months of age. Through expression studies, in silico modelling, 3D morphometry, biochemical studies, and 3D matrix assays, we demonstrate that the inception of the valve disease occurs during foetal life and can be attributed, in part, to a deficiency of interstitial cells to efficiently organize the extracellular matrix (ECM). This ECM organization during foetal valve gestation is due, in part, to molecular interactions between filamin-A, serotonin, and the cross-linking enzyme, transglutaminase-2 (TG2). Pharmacological and genetic perturbations that inhibit serotonin-TG2-filamin-A interactions lead to impaired ECM remodelling and engender progression to a myxomatous valve phenotype.

CONCLUSIONS

These findings illustrate a molecular mechanism by which valve interstitial cells, through a serotonin, TG, and filamin-A pathway, regulate matrix organization during foetal valve development. Additionally, these data indicate that disrupting key regulatory interactions during valve development can set the stage for the generation of postnatal myxomatous valve disease.

Estimate of deaths due to valvular insufficiency attributable to the use of benfluorex in France

PURPOSE

To estimate the number of deaths from valvular insufficiency caused by the use of the fenfluramine-derivative benfluorex during the period 1976-2009 in France.

METHODS

Our calculation was based on (i) the exposure level to benfluorex in the French population, derived from sales figures for the period 1976-2009 and from the main characteristics of benfluorex use provided by the French health products safety agency; (ii) the relative risk of hospitalization for valvular insufficiency among exposed compared with unexposed individuals with diabetes, originating from a cohort study based on a French medico-administrative database, with benfluorex exposure assessed in 2006; (iii) the incidence of hospitalization for valvular insufficiency among exposed individuals, originating from the same database; and (iv) the mortality associated with valvular heart disease.

RESULTS

In France, use of benfluorex during the period 1976-2009 is likely to be responsible for around 3100 hospitalizations and 1300 deaths due to valvular insufficiency. These figures may be underestimations.

CONCLUSIONS

The grave consequences benfluorex use have had for many people lend support to the public investigation, which has been set to understand the reasons that have contributed to the delay in withdrawing benfluorex from the French market.

Does innovation in obesity drugs affect stock markets? An event study analysis

OBJECTIVE

This study empirically analyzes the effects of public information about the pharmaceutical R&D process on the market valuation of the sponsoring firm. We examined the market's response to scientific news and regulatory decisions about an antiobesity drug, rimonabant, and the effects on the sponsoring company (Sanofi-Aventis) and its incumbent competitors (Abbott and Roche).

METHODS

Event study methodology was used to test the null hypothesis of no market response. We covered the full life cycle of rimonabant (1994-2008), using a data set of daily closing price and volume.

RESULTS

The results suggest that scientific news in the initial stages of the drug R&D process (i.e., drug discovery, preclinical and clinical trials) had no significant effects. However, news related to regulatory decisions, such as recall or safety warning, had significant negative effects on the company's market value. No spillover/contagion effects on competitor firms were detected.

CONCLUSION

Market reactions occur at the time when the regulator takes decisions about drugs. Scientific news, even those of high-impact, may pass unnoticed.

Valvular heart disease associated with benfluorex therapy: high prevalence in patients with unexplained restrictive valvular heart disease

AIMS

Restrictive valvular disease (RVD) has recently been reported in patients after benfluorex exposure. However, little is known about its prevalence and echocardiographic features. The aim of our study was to assess the frequency of benfluorex exposure in patients with RVD and to describe their echocardiographic characteristics.

METHODS AND RESULTS

In a single centre study, patients with a final diagnosis of unexplained RVD were studied. Patients were interrogated for their previous use of benfluorex or other appetite-suppressant drugs (ASDs). Forty seven consecutive patients, aged 59 ± 9.6 years, with RVD were found [42 (91%) women]. Among them, 35 (74%) had previous treatment with ASD, including benfluorex in 34 patients. Among the latter, 14 (40%) have been exposed to benfluorex alone, 20 (60%) in combination with another ASD. Echocardiographic features included isolated mitral or aortic restricted valve motion in 19 patients (40%), and combined mitral and aortic involvement in 28 (60%).Twenty-seven (96%) of the latter had been exposed to benfluorex. As compared with the 'no ASD' group (n= 12), patients in the benfluorex group (n= 34) were more frequently female, had more frequent arterial hypertension and hypertriglyceridemia, and presented more frequently with combined mitral and aortic disease (79 vs. 8%, P < 0.001). Valve stenosis and tricuspid involvement were rare in the benfluorex group.

CONCLUSION

The frequency of benfluorex exposure is high in patients with unexplained RVD. Combined aortic and mitral restrictive valve regurgitation is highly suggestive of valvular disease associated with benfluorex or other ASD therapy and may alert clinician about the possibility of this diagnosis.

Aortic valve disease and treatment: the need for naturally engineered solutions

The aortic valve regulates unidirectional flow of oxygenated blood to the myocardium and arterial system. The natural anatomical geometry and microstructural complexity ensures biomechanically and hemodynamically efficient function. The compliant cusps are populated with unique cell phenotypes that continually remodel tissue for long-term durability within an extremely demanding mechanical environment. Alteration from normal valve homeostasis arises from genetic and microenvironmental (mechanical) sources, which lead to congenital and/or premature structural degeneration. Aortic valve stenosis pathobiology shares some features of atherosclerosis, but its final calcification endpoint is distinct. Despite its broad and significant clinical significance, very little is known about the mechanisms of normal valve mechanobiology and mechanisms of disease. This is reflected in the paucity of predictive diagnostic tools, early stage interventional strategies, and stagnation in regenerative medicine innovation. Tissue engineering has unique potential for aortic valve disease therapy, but overcoming current design pitfalls will require even more multidisciplinary effort. This review summarizes the latest advancements in aortic valve research and highlights important future directions.

Regression of cardiac valvulopathy related to ergot-derived dopamine agonists

AIMS

In a previous echocardiographic prevalence study we reported a significant increase in the frequency of heart valve regurgitation in patients with Parkinson's disease taking the ergot-derived dopamine agonists pergolide and cabergoline versus controls. We followed-up our original cohort of patients to ascertain whether valvulopathy regressed after discontinuation of treatment and/or its incidence increased over time.

METHODS

Prospective follow-up of 101 patients treated with ergot-derived dopamine agonists included in the prevalence study: 53 given pergolide and 48 cabergoline (64% male; 66.4 ± 8.7 years of age, 11.5 ± 5.9 years of disease, 21.8 ± 5.9 months of follow-up); 55 stopped treatment while 46 continued. The main outcomes measures, were: echocardiographic quantification of regurgitant valve disease, abnormal leaflet, or cusp thickening and measurement of mitral valve tenting area.

RESULTS

Valve abnormalities regressed in about one third of patients with significant multivalvular and in about half of the patients with monovalvular regurgitation who withdrew; no progression was observed in remaining patients. Patients continuing ergot-derived dopamine agonists showed progression of cardiac valvulopathy: seven new cases with three to four regurgitation grade of any valve occurred during follow-up; this regarded also patients who had been on pergolide for many years.

CONCLUSION

Owing to the persistence of risk of heart valve damage over time and the lack of its mid-term reversibility in many patients, we believe that pergolide and cabergoline should be prescribed only when therapeutic alternatives with a better risk/benefit ratio are unavailable and the patient has access to echocardiography.

Drug-induced fibrotic valvular heart disease

The initial association between the development of valvular heart disease and drugs stems from observations made during the use of methysergide and ergotamine for migraine prophylaxis in the 1960s. Since then, the appetite suppressants fenfluramine and dexfenfluramine, the dopamine agonists pergolide and cabergoline, and more recently, the recreational drug ecstasy (3,4 methylenedioxymethamphetamine; MDMA) have been implicated. Results from clinical trials show that drug dose and treatment duration affect both the risk of developing the disease and its severity. The natural history of the disease remains unclear, although regression of valvular lesions after the end of treatment has been reported. Interference with serotonin metabolism and its associated receptors and transporter gene seems a likely mechanism for development of the drug-induced valvular heart disease. Physicians need to balance the benefits of continued therapy with these drugs against possible risks. Further investigation is needed to assist with treatment decisions. Continued vigilance is necessary because several commonly prescribed treatments interact with serotonergic pathways.

Fenfluramine disrupts the mitral valve interstitial cell response to serotonin

Serotonin (5HT) receptor signaling and 5HT-related agents, such as the anorexogen fenfluramine (Fen), have been associated with heart valve disease. We investigated the hypothesis that Fen may disrupt mitral valve interstitial cell (MVIC) homeostasis through its effects on mitogenesis and extracellular matrix biosynthesis. Normal and myxomatous mitral valves, both human and canine, were harvested, and primary MVIC cultures were established. 5HT caused increased phosphorylation of extracellular signal-related kinase in MVIC; Fen alone did not. However, Fen combined with 5HT increased the level of MVIC extracellular signal-related kinase, when compared with 5HT alone. In addition, MVIC mitogenesis per (3)H-thymidine ((3)HTdR) demonstrated a 5HT dose-dependent increase, with no effect of Fen alone. In contrast, Fen combined with 5HT inhibited the MVIC (3)HTdR response when compared with 5HT alone. Furthermore, fluoxetine, a 5HT transporter inhibitor, while having no effect alone, suppressed Fen-5HT (3)HTdR inhibition when administered with Fen plus 5HT. Finally, MVIC incorporations of (3)H-proline and (3)H-glucosamine, measures of extracellular matrix collagen and glycosaminoglycan respectively, were increased with 5HT alone; however, Fen did not affect MVIC glycosaminoglycan or collagen either alone or in combination with 5HT. Taken together, the ratios of (3)H-proline or (3)H-glycosaminoglycan to (3)HTdR in MVIC, normalized to 5HT alone, demonstrated a significant imbalance of extracellular matrix production versus proliferation in MVIC cultures with Fen plus 5HT exposure. This imbalance may explain in part the pathophysiology of Fen-related mitral valve disease.

Role of serotoninergic pathways in drug-induced valvular heart disease and diagnostic features by echocardiography

Serotonin plays a significant role in the development of carcinoid heart disease, which primarily leads to fibrosis and contraction of right-sided heart valves. Recently, strong evidence has emerged that the use of specific drug classes, such as ergot alkaloids (for migraine headaches), 5-hydroxytryptamine (5-HT or serotonin) uptake regulators or inhibitors (for weight reduction), and ergot-derived dopamine agonists (for Parkinson's disease), can result in left-sided heart valve damage that resembles carcinoid heart disease. Recent studies have suggested that both right-sided and left-sided drug-induced heart valve disease involves increased serotoninergic activity and in particular activation of the 5-HT receptors, including the 5-HT2B receptor subtype, which mediate many of the central and peripheral functions of serotonin. G-proteins that inhibit adenylate cyclase activity mediate the activity of the 5-HT2B receptor subunit, which is widely expressed in a variety of tissues, including liver, lung, heart, and coronary and pulmonary arteries; it has also been reported in embryonic mouse heart, particularly on mouse heart valve leaflets. In this review, the authors discuss the salient features of serotoninergic manifestations of both carcinoid heart disease and drug-induced cardiac valvulopathy, with an emphasis on echocardiographic diagnosis.

Risk of valvular heart disease associated with the use of dopamine agonists in Parkinson's disease: a systematic review

A literature review was conducted to assess risk of cardiac valve regurgitation (CVR) associated with use of ergot-derived and non-ergot dopamine agonists (DAs) in patients with Parkinson's disease (PD).

INCLUSION CRITERIA

case-control/observational studies of >10 patients with PD treated with DAs, including a control group and assessment of incidence/risk of CVR. Of the 166 publications identified, 14 met all inclusion criteria and included 1,750 patients. In 11 of the studies, a significant increase in CVR frequency of any severity (at the aortic, mitral or tricuspid valve) in the ergot group vs. the non-ergot or control group was described. No study reported increased risk of CVR for non-ergot DAs, compared with controls. In the studies identified in the literature, the use of ergot-derived DAs (pergolide and cabergoline) in patients with PD was associated with increased risk of CVR. Increased risk of CVR was not associated with the use of non-ergot DAs.

Prevalence of Unsuspected and Significant Mitral and Aortic Regurgitation

OBJECTIVE

We sought to determine the prevalence of unsuspected, pre-existing valvular regurgitation in a large, heterogeneous population of patients referred for an echocardiogram.

METHODS

The echocardiograms of 6851 consecutive individuals without suspected valve disease were reviewed. Regurgitant severity was graded using a clinical composite of published methods and multiple logistic analyses were used to model various clinical variables.

RESULTS

The overall prevalence of moderate or greater mitral regurgitation (MR) was 11.7% in male patients and 12.5% in female patients. For mild or greater aortic insufficiency (AI), the prevalence was 18.9% in male patients and 19.7% in female patients. Both MR and AI increased exponentially as a function of age. Female sex predicted MR, but AI was sex neutral. Regurgitant severity increased with decreasing ejection fraction and body mass index, a history of hypertension, the presence of left ventricular hypertrophy, and valvular abnormalities.

CONCLUSIONS

The prevalence of unsuspected MR and AI is substantial, increases exponentially with age, and is predicted by commonly used clinical variables.

[Aortic insufficiency under weak doses of cabergoline for non-tumoral hyperprolactinemia]

Used in its neurological indication, cabergoline is known to induce cardiac valve regurgitations, essentially mitral and aortic valvular diseases, by its action on the 5HT2b receptors. Until now, it was assumed that the dose and the duration of exposure were the major factors of appearance. We describe a case of aortic insufficiency which developed in a patient given low doses of cabergoline (0.5 mg weekly) for non-tumoral hyperprolactinemia. Because of previous use of appetite suppressants and of bromocriptine, the exclusive responsibility of cabergoline remained uncertain. The potential gravity of these valvular heart diseases emphasizes the importance of careful cardiologic examination before and during treatment.

Valvular heart disease and the use of dopamine agonists for Parkinson's disease

BACKGROUND

Ergot-derived dopamine receptor agonists, often used in the treatment of Parkinson's disease, have been associated with an increased risk of valvular heart disease.

METHODS

We performed an echocardiographic prevalence study in 155 patients taking dopamine agonists for Parkinson's disease (pergolide, 64 patients; cabergoline, 49; and non-ergot-derived dopamine agonists, 42) and 90 control subjects. Valve regurgitation was assessed according to American Society of Echocardiography recommendations. The mitral-valve tenting area was also measured and used as a quantitative index for leaflet stiffening and apical displacement of leaflet coaptation.

RESULTS

Clinically important regurgitation (moderate to severe, grade 3 to 4) in any valve was found with significantly greater frequency in patients taking pergolide (23.4%) or cabergoline (28.6%) but not in patients taking non-ergot-derived dopamine agonists (0%), as compared with control subjects (5.6%). The relative risk for moderate or severe valve regurgitation in the pergolide group was 6.3 for mitral regurgitation (P=0.008), 4.2 for aortic regurgitation (P=0.01), and 5.6 for tricuspid regurgitation (P=0.16); corresponding relative risks in the cabergoline group were 4.6 (P=0.09), 7.3 (P<0.001), and 5.5 (P=0.12). The mean mitral tenting area was significantly greater in ergot-treated patients and showed a linear relationship with the severity of mitral regurgitation. Patients treated with ergot derivatives who had grade 3 to 4 regurgitation of any valve had received a significantly higher mean cumulative dose of pergolide or cabergoline than had patients with lower grades.

CONCLUSIONS

The frequency of clinically important valve regurgitation was significantly increased in patients taking pergolide or cabergoline, but not in patients taking non-ergot-derived dopamine agonists, as compared with control subjects. These findings should be considered in evaluating the risk-benefit ratio of treatment with ergot derivatives.

Aortic valvular regurgitation: prevalence and clinical characteristics in a predominantly obese adult population not taking anorexigens

BACKGROUND

We recently reported the prevalence of aortic regurgitation (AR) by Doppler echocardiography (echo) in obese subjects to be higher than in some previous reports.

OBJECTIVE

To describe the prevalence of AR in an obese population not taking anorexigens as a function of demographic characteristics, cardiovascular risk factors, and other potential predictors.

METHODS

In 539 adult subjects, cardiovascular status was evaluated by medical history, physical examination, and Doppler echocardiograms performed according to a standardized imaging protocol. Echocardiographic readers were blinded as to each subject's medical and medication histories. Associations of AR with demographic and comorbid factors were examined.

RESULTS

Subjects had a mean (+/- SD) body mass index (BMI) of 35 +/- 7 kg/m2, and were predominantly white (87.6%), females (74%), with a mean age of 47 +/- 12 years. AR by Food and Drug Administration criteria (> or =mild) was present in 4.1% of the subjects. Covariates significantly associated with AR were increasing age (P < 0.001), presence of a history of hypertension (P = 0.001), left ventricular (LV) internal dimensions (P < 0.005), and tricuspid and mitral regurgitation grade (P < 0.001).

CONCLUSIONS

Clinical and Doppler echo evaluation of a large, predominantly obese, adult population revealed that AR was more prevalent than in some previous reports and was highly correlated with increased age, presence of a history of hypertension, LV internal dimensions, tricuspid and mitral regurgitation.

Safety of drug therapies used for weight loss and treatment of obesity

Some of the medications used for weight loss in the management of obesity have been associated with unacceptable morbidity and mortality. Safety concerns have led to the withdrawal of aminorex, followed by the fenfluramines in 1997, and phenylpropanolamine (norephedrine) in 2000. Aminorex was associated with an increased prevalence of primary pulmonary hypertension (PPH), fenfluramines with an increased prevalence of PPH and valvulopathy, and phenylpropanolamine with an increased risk of haemorrhagic stroke. Several studies have investigated the safety of the fenfluramines, yet the benefit-risk profile has not been conclusively quantified. This is due to several deficiencies in the published studies, including a lack of data on the baseline prevalences of comorbid conditions in obese subjects, and potential confounders and biases in the study designs. Although several studies and systematic reviews support an increased risk of PPH and valvulopathy in patients who have taken fenfluramines, without knowledge of the background prevalence it is not possible to determine if the exposure preceded the outcome. The population at higher risk of these adverse effects includes those taking higher doses or with a longer duration of exposure to fenfluramines and those with pre-existing cardiac disease or a genetic predisposition. Patients exposed to fenfluramines continue to be monitored, with some follow-up studies indicating no overall worsening in valvulopathy over time. There are limited efficacy and safety data for amfepramone (diethylpropion) and phentermine and their approval for the management of obesity is limited to short-term use. Orlistat and sibutramine are the only currently approved medications for long-term management of obesity. Although the benefit-risk profiles of sibutramine and orlistat appear positive, sibutramine continues to be monitored because of long-term safety concerns. The safety and efficacy of currently approved drug therapies have not been evaluated in children and elderly patient populations and there is limited information in adolescents, whilst the long-term safety of current and potential new drug therapies in adults will require several years of postmarketing surveillance to fully elucidate their adverse effect profiles.

Natural history of valvular regurgitation using side-by-side echocardiographic analysis in anorexigen-treated subjects

In 1997, the US Food and Drug Administration (FDA) reported valvular regurgitation (aortic regurgitation [AR] mild or greater and/or mitral regurgitation [MR] moderate or greater) in 32.8% of patients treated with anorexigens. This study sought to determine the natural history of valvular regurgitation in patients who were included in the FDA's original report. This was a nonrandomized, natural history study of these subjects. Cohort I consisted of 155 of 186 patients (83%) who were reported to the FDA. Cohort II consisted of a similar group of 311 patients who were not included. Initial echocardiograms were obtained for medical indications before the study initiation, and study echocardiograms were standardized and obtained at 3-month intervals. Level III echocardiographers performed blinded, side-by-side comparison of the first and last study echocardiograms at a core laboratory. Cohorts I and II consisted of predominantly female, middle-aged, obese subjects. At enrollment, patients in cohorts I and II had mild or greater AR (17.9%, 13.5%) and moderate or greater MR (3.3%, 4.0%), respectively, which was less than in the FDA's report. At follow-up, there were no statistically significant changes in the degree of valvular regurgitation in either cohort when the first and last study echocardiograms were read side by side. In conclusion, this natural history follow-up study demonstrates that MR and AR in long-term anorexigen-treated patients was less than reported to the FDA, did not progress, and remained echocardiographically stable during the 10-month duration of the study.

Treatment of Parkinson's disease with pergolide and relation to restrictive valvular heart disease

BACKGROUND

Restrictive valvular heart disease has been reported in patients with Parkinson's disease treated with pergolide. However, few data are available on frequency, severity, dose dependency, and reversibility of pergolide-induced disease, nor on the pulmonary pressures of these patients. We aimed to clarify these characteristics in a large group of patients.

METHODS

78 patients with Parkinson's disease treated with pergolide and 18 never treated with an ergot-derived dopamine agonist (controls) were evaluated by echocardiography. A valvular scoring system was used, ranging from 1 (proven ergot-like restrictive valvular heart disease) to 4 (no disease). For the mitral valve, tenting areas and tenting distances were measured. Systolic pulmonary artery pressures were derived from the tricuspid regurgitant jet.

FINDINGS

Restrictive valvular heart disease of any type was present in 26 (33%) patients in the pergolide group and none in controls (p=0.0025). Important disease (score 1 or 2) was present in 15 (19%) patients in the pergolide group and none in controls (p=0.066). Mean tenting distances and tenting areas of the mitral valve were 1.08 cm (range 0.55-2.66) and 2.39 cm2 (0.88-4.59) in the restrictive mitral valve group versus 0.63 cm (0.22-1.20) and 1.39 cm2 (0.39-3.23) in the non-restrictive group (p=0.003 and p<0.0001, respectively). Significant correlation was noted between cumulative doses of pergolide and tenting areas of the mitral valves (r=0.412, p=0.017). Mean systolic pulmonary artery pressures were 39.3 mm Hg (range 25-71) in the high-dose group versus 38.5 mm Hg (20-65) in the low-dose group (p=0.76) and 31 mm Hg (25-40) in controls (p=0.02 vs all patients given pergolide). In six patients, pergolide treatment was stopped because of restrictive valvular heart disease, in two of whom regression of disease was shown.

INTERPRETATION

Restrictive valvular heart disease is not a rare finding in patients treated with pergolide. Clinicians should consider changing to a non-ergot drug if this disease is diagnosed.

Risk of valvular heart disease associated with use of fenfluramine

BACKGROUND

Estimates of excess risk of valvular heart disease among prior users of fenfluramine and dexfenfluramine have varied widely. Two major forms of bias appear to contribute to this variability and also result in a systematic under-estimation of risk. The first, a form of nondifferential misclassification, is the result of including background, prevalent cases among both exposed and unexposed persons in calculations of risk. The second bias results from not considering the relatively short duration of exposure to drugs.

METHODS

We examined data from all available echocardiographic studies reporting the prevalence of aortic regurgitation (AR) and mitral regurgitation (MR) among persons exposed to fenfluramine or dexfenfluramine and a suitable control group. We also included one study in which previously existing AR or MR had been excluded. We corrected for background prevalent cases, estimated incidence rates in unexposed persons, and performed a person-years analysis of apparent incidence rates based on exposure time to provide an unbiased estimate of relative risk.

RESULTS

Appearance of new AR was strongly related to duration of exposure (R2 = 0.75, p < 0.0001). The summary relative risk for mild or greater AR was 19.6 (95% CI 16.3-23.5, p < 0.00001); for moderate or greater MR it was 5.9 (95% CI 4.0-8.6, p < 0.00001).

CONCLUSION

These findings provide strong support for the view that fenfluramine and dexfenfluramine are potent causal factors in the development of both aortic and mitral valvular heart disease.

Pharmacotherapy of obesity

The growing recognition of the health risks of obesity coupled with the difficulties in treating it successfully by lifestyle modification predicates a need for effective drug treatment. The history of drug treatment in the second half of the 20th century is, however, one of disappointment and concern over drug toxicity. However, the advances in our understanding of the mechanism of weight control, together with improved ways of evaluating anti-obesity drugs, has resulted in two effective compounds, sibutramine and orlistat, becoming available for clinical use. Sibutramine has actions on both energy intake and expenditure and had been shown to enhance weight loss and weight maintenance achieved by diet, in simple obesity as well as when accompanied by complications of diabetes or hypertension. About 50-80% of patients can achieve a >5% loss, significantly more than if patients receive the same lifestyle intervention with placebo. Orlistat, which acts peripherally to block the absorption of dietary fat, has had similar results in clinical trials; a recent study (XENDOS) has just reported results which show that the enhanced, albeit modest, weight loss achieved with orlistat delays the development of diabetes over a 4-year period. A number of other compounds are expected to complete or enter clinical trials over the next decade. There is considerable optimism that we will soon have the pharmacological tools needed to make the treatment of obesity feasible.

Effect of fenfluramine-derivative diet pills on cardiac valves: a meta-analysis of observational studies

BACKGROUND

Fenfluramine-derivative diet pills were withdrawn from the market in 1997 because of an association with valvular regurgitation, but subsequent estimates of the prevalence of this condition have varied widely. We systematically reviewed evidence regarding the prevalence of valvular disease after fenfluramine exposure.

METHODS

We searched multiple databases with multiple search terms. Conference proceedings from 1997 onward were searched by index. Authors of eligible studies were contacted to identify unpublished works. Selection criteria were liberally determined. Ten of the identified 11 articles met these criteria. Reviewers assessed the studies' methodologic quality by use of a standard form to evaluate selection, attrition, performance, and detection bias. The studies were analyzed in 2 groups on the basis of length of exposure (<90 days or >90 days). The Mantel-Haenszel method was used to summarize data. Quantitative and qualitative tests for heterogeneity were performed. Tests for publication bias were also done.

RESULTS

Tests for heterogeneity were nonsignificant after removing 1 outlier trial. The pooled prevalence of valvular regurgitation meeting Food and Drug Administration criteria (at least mild aortic regurgitation or at least moderate mitral regurgitation) among patients treated for >90 days was 12.0% compared with 5.9% for the unexposed group (prevalence odds ratio 2.2, 95% CI 1.7-2.7). The combined analyses also identified a small but statistically significant increase in mitral regurgitation not previously identified by individual studies (exposed 3.5%, unexposed 1.8%, prevalence odds ratio 1.6, 95% CI 1.05-2.3). Among patients exposed for <90 days, a trend toward more regurgitation was not statistically significant by either combined Food and Drug Administration criteria (exposed 6.8%, unexposed 5.8%, prevalence odds ratio 1.4, 95% CI 0.8-2.4) or by individual valve.

CONCLUSIONS

These data indicate that fenfluramine-associated valvular regurgitation is less common than initially reported, but still present in 1 of 8 patients treated for >90 days.

Effects of sibutramine on ventricular dimensions and heart valves in obese patients during weight reduction

BACKGROUND

Obesity enhances hemodynamic alterations that predispose to a subsequent increase in left ventricular (LV) wall stress leading to LV hypertrophy. In obese subjects, weight reduction regresses LV mass (LVM), regardless of blood pressure. Sibutramine can increase blood pressure and heart rate, which may attenuate the reductions in LVM associated with weight loss.

METHODS

Outpatients (n = 184, age 18-65 y, body mass index > or =30 to <40 kg/m2) were randomly assigned to 6 months of once daily double-blind treatment with sibutramine 10 mg or 20 mg, or placebo. LV dimensions, status and function of the valves, weight loss, blood pressure, heart rate, and electrocardiogram were assessed.

RESULTS

For end point data sets, the mean +/- SD LVM index (LVM/height) changes were -3.0 +/- 11.9 g/m for placebo (n = 56), -4.4 +/- 10.7 g/m for sibutramine 10 mg (n = 61), and -4.3 +/- 10.9 g/m for sibutramine 20 mg (n = 56). The reductions observed in the sibutramine groups were statistically significant compared with baseline (P <.01), but pairwise comparison results with placebo were not statistically significant. There was no difference in overall status of the cardiac valves. A statistically significant greater weight loss was found in patients on both doses of sibutramine compared with placebo (P <.001). No statistically significant differences between the groups were observed in respect to blood pressure and electrocardiographic intervals, but a statistically significant increase in pulse rate (7 beats/min) was noted for patients with sibutramine treatment.

CONCLUSION

A 6-month treatment with sibutramine does not affect ventricular dimensions, heart valves, and electrocardiogram variables.

Appetite suppressants and valvular heart disease

Appetite suppressants fenfluramine, dexfenfluramine, and phentermine have been used alone or in combination as an alternative to diet and surgery in the management of obesity. This therapy was halted in 1997 after reports of valvular lesions affecting almost one third of patients treated with these drugs. Fortunately, most cases of appetite suppressant-related valve disease are mild or moderate and rarely required valve repair or replacement. Follow-up studies have suggested improvement in valvulopathy after discontinuation of the treatment. The mechanism of valve disease induced by these drugs is speculative and may be related to their serotonergic effects. Echocardiographic features are similar to carcinoid heart disease and valvulopathy associated with ergot use. Most cases require only follow-up and endocarditis prophylaxis; surgery is rarely needed.

Appetite suppressants and valvular heart disease - a systematic review

BACKGROUND

Although appetite suppressants have been implicated in the development of valvular heart disease, the exact level of risk is still uncertain. Initial studies suggested that as many as 1 in 3 exposed patients were affected, but subsequent research has yielded substantially different figures. Our objective was to systematically assess the risk of valvular heart disease with appetite suppressants.

METHODS

We accepted studies involving obese patients treated with any of the following appetite suppressants: fenfluramine, dexfenfluramine, and phentermine. Three types of studies were reviewed: controlled and uncontrolled observational studies, and randomized controlled trials. Outcomes of interest were echocardiographically detectable aortic regurgitation of mild or greater severity, or mitral regurgitation of moderate or greater severity.

RESULTS

Of the 1279 patients evaluated in seven uncontrolled cohort studies, 236 (18%) and 60 (5%) were found to have aortic and mitral regurgitation, respectively. Pooled data from six controlled cohort studies yielded, for aortic regurgitation, a relative risk ratio of 2.32 (95% confidence intervals 1.79 to 3.01, p < 0.00001) and an attributable rate of 4.9%, and for mitral regurgitation, a relative risk ratio of 1.55 (95% confidence intervals 1.06 to 2.25, p = 0.02) with an attributable rate of 1.0%. Only one case of valvular heart disease was detected in 57 randomized controlled trials, but this was judged unrelated to drug therapy.

CONCLUSIONS

The risk of valvular heart disease is significantly increased by the appetite suppressants reviewed here. Nevertheless, when considering all the evidence, valvulopathy is much less common than suggested by the initial, less methodologically rigorous studies.

Testing the test: the reliability of echocardiography in the sequential assessment of valvular regurgitation

BACKGROUND AND OBJECTIVE

Substantial variability in serial echocardiographic qualitative assessment of valvular regurgitation may exist. Reader variability is generally well understood, but acquisition variability (portions of variability caused by equipment, sonographers, physiologic changes) has been less frequently assessed, particularly in combination with reader variability. We attempted to determine the relative contributions of acquisition and reader variability as components of total test-retest variability for aortic (AR) and mitral (MR) regurgitation.

METHODS

Outpatient echocardiographic study was done at 2 clinical sites. Twenty-three predominantly obese middle-aged females had 3 echocardiograms, 2 performed 14 +/- 3 days apart and the third performed within 1 to 2 hours of the second. Triplets of echocardiograms were evaluated for change in grade of AR and MR. Medical history, anthropometrics, and blood pressures were obtained.

RESULTS

Average intrareader variability (percentage of reads for which there is within-reader disagreement) was 5.6% for AR and 16.7% for MR. The average total test-retest variability (percentage of reads for which there is disagreement between visits) was 29.0% for AR and 24.6% for MR. The acquisition variability for AR was 23.4% +/- 7.7%; for MR, it was 7.9% +/- 10.2%. A significant predictor of change for AR/MR was the initial grade. Change in diastolic blood pressure was positively associated with change in AR and MR.

CONCLUSIONS

Intrareader agreement was substantial for AR and MR. Components of total test-retest variability found were reader, biological (change in diastolic blood pressure), and regression to the mean. Recommendations for clinical practice include monitoring blood pressure changes and understanding the confidence limits of the clinical test. Test-retest variability and its components should be considered in echocardiography and other diagnostic testing.

Appetite suppressants and valvular heart disease in a population-based sample: the HyperGEN study

PURPOSE

Previous studies of the association between the use of appetite suppressants and valvular heart disease have not accounted for the effects of valvular structure and aortic root diameter, which are associated with obesity. We assessed whether the use of the appetite suppressants fenfluramine/dexfenfluramine, either alone or with phentermine, was associated with aortic regurgitation while adjusting for these variables.

SUBJECTS AND METHODS

The sample included 2524 adult participants in the population-based Hypertension Genetic Epidemiology Network study. Information regarding current drug use was assessed during a clinical examination. Medication use was continued at the time of echocardiographic study. Expert readers blinded to current therapy read echocardiograms centrally at Cornell Medical Center. Analyses of the associations between use of fenfluramine/dexfenfluramine (alone or with phentermine) and aortic regurgitation adjusted for potential confounders, including aortic root dilatation and valve fibrocalcification.

RESULTS

Nineteen participants, all of whom had hypertension, were being treated with fenfluramine or dexfenfluramine (5 on these agents alone, 14 also with phentermine). Aortic regurgitation was present in 32% (n = 6) of those taking fenfluramine or dexfenfluramine versus 6% (162/2505) of remaining subjects (P = 0.001). In multivariate-adjusted analyses, treatment with fenfluramine or dexfenfluramine was associated with aortic regurgitation (odds ratio [OR] = 4.9; 95% confidence interval [CI]: 1.7 to 14) and aortic fibrocalcification (OR = 5.2; 95% CI: 1.9 to 15).

CONCLUSION

In a population-based sample, use of fenfluramine or dexfenfluramine, alone or in combination with phentermine, was associated with aortic regurgitation independent of aortic dilatation or fibrocalcification.

Reversal of Phen-Fen associated valvular regurgitation documented by serial echocardiography

We report a case of anorexigen-associated moderate to severe aortic and mitral regurgitation in which the regression of lesions was marked and well documented over more than 2 years. The stability of our patient, as well as the degree of regression of regurgitation documented in our patient, and others, suggests it is prudent both to observe such patients and to avoid operation until such observation has been carried out.

Diet medications and valvular hearl disease: the current evidence

Since 1997, the appetite suppressant drugs fenfluramine-phentermine (fen-phen) and dexfenfluramine have been associated with the development of valvular heart disease. As a result, the drugs have been withdrawn from the market and interim recommendations for evaluation and treatment of exposed patients were issued. However, subsequent studies showed lower prevalence rates for valve abnormalities than were initially reported, and the possibility of such drug-induced lesions resolving has been raised. This article reviews relevant evidence and discusses concerns for the dental practitioner.

Obesity pharmacology: past, present, and future

Over the past several years, the pharmacologic treatment of obesity has undergone changes in safety, efficacy, and therapeutic targeting. The prevalence of cardiac valvulopathy associated with treatment with phentermine, fenfluramine, and dexfenfluramine is now becoming clarified with the publication of longer-term studies. Phenylpropanolamine, a well-known over-the-counter appetite suppressant, was recently removed from the market in the United States because of an increased risk of hemorrhagic stroke in women. In contrast, two currently approved medications, sibutramine and orlistat, have been shown to be safe and moderately effective for weight loss with documented beneficial effects on cardiovascular risk factors. Three other drugs, bupropion, topiramate, and ciliary neurotrophic factor, are undergoing clinical trials for obesity based on empirical observations. Most promising are the advances in genetics and molecular biology that are beginning to elucidate new targets for controlling appetite and energy utilization. These therapeutic agents will likely herald a second generation of anti-obesity medications over the next decade.

Low risk of significant echocardiographic valvulopathy in patients treated with anorectic drugs

BACKGROUND

Phentermine--fenfluramine and dexfenfluramine use for weight loss has been previously associated with increased prevalence of valvular heart disease. This association was initially based on small numbers of patients, limited data on dose and duration of drug therapy, and no correlation with matched controls.

METHODS

Our investigation involved 343 obese subjects enrolled in a prospective, strict weight loss, research protocol from September 1994 to September 1997. All subjects underwent transthoracic echocardiography for significant valvular lesions within a mean of 121 days from the manufacturer's announcement of the voluntary withdrawal of fenfluramine and dexfenfluramine from the market. All echocardiograms were interpreted by 2 independent readers.

RESULTS

The study population included 281 females and 62 males with a mean age of 46.7+/-9.1 years and mean initial body mass index of 40.1+/-8.1 kg/m(2). Using the Food and Drug Administration's criteria, only 21 subjects (6.1%) had significant valvular lesions. Aortic regurgitation was detected in 18 subjects, mitral regurgitation in 3 subjects, and both aortic and mitral regurgitation in 1 subject; no one had severe regurgitation. Significant valvular disease did not correlate with age, gender, initial/ending body mass index, the drug dose, duration of drug therapy, or serotonin reuptake inhibitors.

CONCLUSIONS

Anorexigen therapy is associated with a low prevalence of significant valvular regurgitation. Late valvular abnormalities from drug treatment await long term prospective studies.

Appetite suppressants and valvular heart disease

The association between valvular heart disease and diet pills was discovered several years ago in a small cohort of patients. Subsequent uncontrolled surveys and reports suggested a prevalence of cardiac abnormalities as high as 30%. These results led to widespread concern by millions of appetite suppressant users and the withdrawal of both fenfluramine and dexfenfluramine from the market. Through this review of the literature, it becomes apparent that we have better defined the association between valvular heart disease and appetite suppressants; nonetheless, many questions and controversies remain. Most large scale, multicenter, controlled studies have shown that a prevalence of significant valve regurgitation is between 2 and 12% and that the likelihood of disease increases with increasing dose and/or duration of appetite suppressant use, but several other issues, such as the mechanism of action, remain unanswered.

Transesophageal echocardiographic (TEE) evaluation of the aortic valve, left ventricular outflow tract, and pulmonic valve

The most important role of TEE in aortic valve disease is in the diagnosis of endocarditis and its complications. Examination of the annulus and subvalvular region is essential in any patient with possible aortic valve endocarditis. Assessment of the severity of aortic stenosis is a useful application of TEE when other data are either inconsistent or unavailable. TEE can provide a diagnosis of the origin of acute severe aortic insufficiency; this information may play a critical role in surgical planning. The diagnosis of a variety of aortic valve diseases can be made when TEE is performed to find an embolic source or to rule out dissection. In the case of mass lesions, such as papillary fibroelastomas and Libman-Sacks vegetations, the results of TEE carry major therapeutic implications. TEE offers generally excellent quality images of the LVOT and images of the RVOT and pulmonic valve that are superior to transthoracic echocardiography. The major clinical usefulness of TEE stems from its ability to identify pulmonic valve mass lesions and the causes of left and right ventricular outflow obstruction. TEE is also an important adjunct in the surgical management of left ventricular outflow obstruction.

Prevalence and diagnostic value of precordial murmurs for valvular regurgitation in obese patients treated with dexfenfluramine

Echocardiography is recommended for the detection of valvular regurgitation in asymptomatic users of anorexigens with a heart murmur. To determine the prevalence and diagnostic value of heart murmurs for valvular regurgitation, 223 patients receiving dexfenfluramine therapy for 6.9 months and 189 matched controls underwent history and cardiac auscultation by experienced noncardiologists unaware of echocardiography. Color Doppler echocardiograms were interpreted by 3 observers unaware of patients' clinical data. The frequency of at least mild regurgitation of any valve and abnormal regurgitation (moderate mitral or tricuspid or mild aortic regurgitation) were determined. Heart murmurs heard in 31 dexfenfluramine users (14%) and in 20 controls (11%) were all systolic and of grade I to II/VI intensity. Mild or worse regurgitation of any valve showed a trend in patients (18% vs 11.6% in controls, odds ratio [OR] 1.66, confidence interval [CI] 0.95 to 2.9, p = 0.08), but abnormal regurgitation (includes Food and Drug Administration grade regurgitation) was more common in patients (9% vs 3% in controls, OR 3.0, CI 1.18 to 7.65, p = 0.02). In dexfenfluramine users, heart murmurs were associated with at least mild or abnormal regurgitation (OR 3.1 and 3.05, 95% CI 1.34 to 7.13 and 1.1 to 8.67; p = 0.008 and 0.036, respectively), had a specificity of 89% and 88%, negative predictive value of 85% and 93%, but sensitivity of 37% and 30%, and positive predictive value of 35% and 19%, respectively. Most valves missed by cardiac auscultation had normal morphology and mild regurgitation. Finally, heart murmurs had better diagnostic value for either type of valvular regurgitation than heart murmurs and clinical variables or clinical variables alone. In summary, in dexfenfluramine users the prevalence of heart murmurs was low and their absence predicted absence of mild or worse regurgitation of any valve or abnormal valvular regurgitation. Therefore, cardiac auscultation should be the screening method of choice for detecting valvular regurgitation in users of anorexigens.

Diet drug-related cardiac valve disease: the Mayo Clinic echocardiographic laboratory experience

OBJECTIVE

To describe the prevalence of diet drug-related valvular disease among our referral population and the association of valvular disease with duration of exposure to fenfluramine and phentermine in combination and to dexfenfluramine alone.

PATIENTS AND METHODS

In this retrospective review of clinical and echocardiographic data, charts of patients referred for treatment of toxic effects of diet drugs were reviewed, and telephone interviews were conducted.

RESULTS

Between June and December 1997, 191 patients (164 women, 27 men; mean age, 47 years) were referred for possible diet drug-related valvular disease. Twenty-eight (28%) of the 99 asymptomatic patients and 40 (43%) of the 92 symptomatic patients had abnormal echocardiographic findings. Valvular lesions among the 68 patients with abnormal echocardiographic findings included mild (or greater) aortic regurgitation in 55 patients (81%), moderate (or greater) mitral regurgitation in 12 (18%), and moderate (or greater) tricuspid regurgitation in 7 (10%). The Food and Drug Administration case definition of diet drug-related valvulopathy was noted in 31 % of this referral population. Of patients with valvulopathy, mean duration of therapy with fenfluramine and phentermine in combination and dexfenfluramine alone was 9 months and 5 months, respectively. Duration of therapy was not associated with presence or absence of disease. Five patients had surgical intervention for severe valvulopathy: 3 had mitral valve repair, 1 had mitral valve replacement, and 1 had aortic valve replacement. Pulmonary hypertension (>40 mm Hg) was found in 24 patients (13%), and 17 (71 %) had pulmonary hypertension in association with valvulopathy.

CONCLUSION

This study demonstrated a 31% (60/191) prevalence of valvulopathy in patients with a history of diet drug exposure who were referred for echocardiographic evaluation. The most common finding was mild aortic regurgitation. Twenty-eight percent of asymptomatic patients had abnormal echocardiographic findings. This study emphasizes the spectrum of diet drug-related cardiac disease and the potential for valvulopathy in asymptomatic patients.