The long-term outcomes of transcoronary ablation of septal hypertrophy compared to surgical myectomy in patients with symptomatic hypertrophic obstructive cardiomyopathy.

OBJECTIVES: The aim of this study was to compare the long-term outcomes of transcoronary ablation of septal hypertrophy (TASH) with open surgical myomectomy (SM) in patients with symptomatic hypertrophic obstructive cardiomyopathy (HOCM). METHODS: We reviewed patients who underwent either procedure at our institution. The demographics, clinical outcomes, echocardiographic parameters, and complications were compared. RESULTS: Seventy patients with HOCM were treated with either TASH (n = 47, 26 male) or SM (n = 23, 10 male). Compared to those treated with SM, patients undergoing TASH were older (57+/- 14.7 years versus 47 +/- 20.6 years, P = 0.021) and more symptomatic. A higher proportion of patients had syncope as a presenting feature in the TASH group compared to the SM group (57.5% vs. 17.4%, P = 0.002) respectively. They were also more likely to be in New York Heart Association (NYHA) class III/IV compared to the patients who underwent SM (85.1% vs. 39.1%; P < 0.001). Patients were followed for a mean period of 43 months (TASH) and 46 months (SM). Repeat procedures were more common in the TASH group (17% vs. 0%, P = 0.04) but mitral valve replacement was more common in the SM group (0% vs. 8.7%, P = 0.105). Symptom improvement, the rate of complications and all cause mortality rates were similar in both groups. CONCLUSIONS: TASH compares favorably with surgical myectomy with regard to symptom resolution, rate of complications and mortality in a tertiary referral centre and should be seen as an attractive alternative to surgical myectomy in the appropriate patient population.

Cardiac troponin may be released by ischemia alone, without necrosis.

Whilst it is formally stated that cardiac troponin is only released when cardiac myocytes undergo necrosis, there are a number of clinical situations where troponin is present in the circulation, without any apparent cardiac injury. In these cases, troponin half-life in the circulation is usually substantially shorter than that seen when troponin is released following myocardial infarction with frank necrosis. A mechanism has been described in liver, where large cytoplasmic molecules can pass from the intra- to extra-cellular space without cellular necrosis occurring. This occurs by the formation of membranous blebs which bud off from the plasma membrane of the cell. Blebs develop during cellular ischemia. If the ischemia is limited and re-oxygenation occurs, the blebs may be released into the circulation without rupture of the plasma membrane, resulting in a one-off release of cytoplasmic contents including macromolecules. Evidence from cardiac studies is presented supporting the presence of membranous blebs in cardiac myocytes, enabling troponin to be released from cardiac cells due to ischemia alone, without necrosis.

Differences in treatment and management of indigenous and non-indigenous patients presenting with chest pain: results of the Heart Protection Partnership (HPP) study.

BACKGROUND: Indigenous patients with acute coronary syndromes represent a high-risk group. There are however few contemporary datasets addressing differences in the presentation and management of Indigenous and non-Indigenous patients with chest pain. METHODS: The Heart Protection Project, is a multicentre retrospective audit of consecutive medical records from patients presenting with chest pain. Patients were identified as Indigenous or non-Indigenous, and time to presentation and cardiac investigations as well as rates of cardiac investigations and procedures were compared between the two groups. RESULTS: Of the 2380 patients included, 199 (8.4%) identified as Indigenous, and 2174 (91.6%) as non-Indigenous. Indigenous patients were younger, had higher rates hyperlipidaemia, diabetes, smoking, known coronary artery disease and a lower rate of prior PCI; and were significantly less likely to have private health insurance, be admitted to an interventional facility or to have a cardiologist as primary physician. Following adjustment for difference in baseline characteristics, Indigenous patients had comparable rates of cardiac investigations and delay times to presentation and investigations. CONCLUSIONS: Although the Indigenous population was identified as a high-risk group, in this analysis of selected Australian hospitals there were no significant differences in treatment or management of Indigenous patients in comparison to non-Indigenous.

Percutaneous balloon mitral commissurotomy in indigenous versus non-indigenous Australians.

BACKGROUND: Rheumatic heart disease remains a serious health issue amongst the Australian indigenous population. Percutaneous balloon mitral commissurotomy (PBMC) has become the treatment of choice in patients with symptomatic pure mitral stenosis with favourable valve morphology. There is little published data on the efficacy of PBMC in indigenous Australians. AIMS: We sought to document differences between indigenous Australians (IA) and non-indigenous Australians (NIA) undergoing percutaneous balloon mitral commissurotomy (PBMC) at The Prince Charles Hospital and Holy Spirit Northside Hospital from 1990 to 2006. METHODS: PBMC was performed in 327 patients using the Inoue-balloon technique (271 female, 56 male, age +/-15 years (mean+/-S.D.), (range 13-89) between March 1990 and March 2006. RESULTS: The IA population was over represented in this cohort (11% versus an estimated 3.4% of the Queensland population) and comprised the largest non-Caucasian group. Compared with the NIA population they were younger (mean age 36 years (+/-13) versus mean 52(+/-14) years (P<0.05)). Baseline mitral valve area (MVA) was similar in the IA and NIA groups (0.96 cm(2) versus 1.08 cm(2)P=0.9). Mitral valve Echo-score was also similar between the two groups (mean score 7.36 versus 7.52 P=0.8). The IA population had higher pre-procedural mitral valve gradients (14.3 mmHg versus 11.1 mmHg, P<0.05), but less mitral valve calcification. Procedural success was achieved in 91% of both groups. Post procedural MVA (planimetry) was similar (1.98 cm(2) versus 1.84 cm(2)P=0.6), as was percent reduction in mitral valve gradient. Inadequate dilatation was seen in 1 (3%) IA and in 10 (3.6%) of the NIA group. Significant MR was seen in 2 (6%) IA patients and 11 (4%) NIA patients. There were no deaths or strokes or pericardiocenteses in either group. CONCLUSION: The indigenous population makes up a significant proportion of patients requiring PBMC in Queensland. They present younger and with higher mitral valve gradients. The procedure is safe in both the indigenous and non-indigenous Australian population. Further research is required to establish the long-term efficacy of this procedure in indigenous Australians.

Comparison of abciximab with "high-dose" tirofiban in patients undergoing percutaneous coronary intervention.

BACKGROUND: The TARGET study has been criticised for sub-optimal platelet inhibition with tirofiban. We aimed to compare a high-dose bolus regimen of tirofiban (hd-tirofiban) to standard dose of abciximab for patients undergoing percutaneous coronary intervention (PCI). METHODS: We assessed consecutive patients who received either hd-tirofiban (25 mcg/kg bolus followed by 0.15 mcg/kg/min infusion for 18 h) or standard dose abciximab. In-hospital and 6-month outcomes were obtained in all cases. RESULTS: Over an 18-month period, 109 patients who received hd-tirofiban were compared with 110 patients who received abciximab. Both hd-tirofiban and abciximab groups had acute coronary syndromes in 86% and 80% and diabetes in 10% and 13% respectively. Most patients had coronary stent implantation (96% vs. 98%). Thrombocytopenia (platelet count< 100,000) developed in 0.9% of patients receiving hd-tirofiban and 2% of patients receiving abciximab (p = 0.566). Bleeding requiring transfusion occurred in 7.3% and 3% of patients respectively (p = 0.118). Peri-procedural troponin rise was 0.9% in patients receiving hd-tirofiban and 5.5% in patients receiving abciximab (p = 0.07). MACE (Myocardial infarction, Stroke, Revascularisation and Death) at 6 months was 23% in the hd-tirofiban group and 20% in the abciximab group (p = 0.711). The pharmaceutical costs were AUD 322 for hd-tirofiban (one ampoule) and AUD 1,350 for abciximab (3 ampoules). CONCLUSION: There was a small increase in bleeding requiring transfusion and a lower rate of peri-procedural troponin rise in the hd-tirofiban group however, the overall 6-month MACE rates were similar in both groups. There was a considerable cost-saving with the use of hd-tirofiban. A prospective randomised trial of hd-tirofiban vs. abciximab is warranted.

Point-of-care testing shows clinically relevant variation in the degree of inhibition of platelets by standard-dose abciximab therapy during percutaneous coronary intervention.

Administration of GP IIb/IIIa inhibitors during percutaneous coronary intervention (PCI) has proven clinical benefit, but is administered at a dose allowing for the patients' weight but not other variables. This study of 75 patients evaluated platelet inhibition achieved by standard-dose abciximab therapy during PCI as measured by two point-of-care (POC) instruments, Plateletworks (PW) and whole blood aggregation (WB). Results were related to the decrease of platelet activation produced as well as patients' return of angina within 30 days. Flow cytometric measurement showed abciximab suppressed platelet-monocyte aggregates (P < 0.001) and activated glycoprotein IIb/IIIa (P < 0.001) but not P-selectin. Greater POC-measured inhibition corresponded to less postabciximab expression of platelet-monocyte aggregates (P < 0.01). Patients above the lowest quartile of POC inhibition with PW demonstrated a relative risk of experiencing return of angina within 30 days of 0.48 (0.23-0.99). In conclusion, POC measurements reflect platelet activation suppression, higher PW measurements being associated with a decreased risk of return of angina.

Coronary stenting for a muscular bridge in a patient with hypertrophic obstructive cardiomyopathy.

A young woman with hypertrophic cardiomyopathy presented with intractable chest pain due to a myocardial bridge over the left anterior descending artery, producing severe compression during systole. Percutaneous intracoronary stenting was performed. The patient, however, developed severe and diffuse restenosis within 30 days of the procedure. Myotomy may provide a more effective treatment option for such patients with symptomatic myocardial bridging.

Perceived stress as a predictor of the self-reported new diagnosis of symptomatic CHD in older women.

This article describes one aspect of a prospective cohort study of 10,432 women aged between 70 and 75 years. After a 3-year period, 503 women self-reported a new diagnosis by a doctor of angina or myocardial infarction (symptomatic coronary heart disease [CHD]). Time one psychosocial variables (Duke Social Support Index, time pressure, Perceived Stress Scale, Mental Health Index, having a partner, educational attainment, and location of residence) were analyzed using univariate binary logistic regression for their ability to predict subsequent symptomatic CHD. Of these variables, the Duke Social Support Index, Perceived Stress Scale and the Mental Health Index were found to be significant predictors of symptomatic CHD diagnosis. Only the Perceived Stress Scale, however, proved to be a significant independent predictor. After controlling for time one nonpsychosocial variables, as well as the frequency of family doctor visits, perceived stress remained a significant predictor of the new diagnosis of symptomatic CHD in this cohort of older women over a 3-year period.

Use of an accelerated chest pain assessment protocol in patients at intermediate risk of adverse cardiac events.

OBJECTIVE: To determine the feasibility, safety and effectiveness of a structured clinical pathway for stratification and management of patients presenting with chest pain and classified as having intermediate risk of adverse cardiac outcomes in the subsequent six months. DESIGN: Prospective clinical audit. PARTICIPANTS AND SETTING: 630 consecutive patients who presented to the emergency department of a metropolitan tertiary care hospital between January 2000 and June 2001 with chest pain and intermediate-risk features. INTERVENTION: Use of the Accelerated Chest Pain Assessment Protocol (ACPAP), as advocated by the "Management of unstable angina guidelines--2000" from the National Heart Foundation and the Cardiac Society of Australia and New Zealand. MAIN OUTCOME MEASURE: Adverse cardiac events during six-month follow-up. RESULTS: 409 patients (65%) were reclassified as low risk and discharged at a mean of 14 hours after assessment in the chest pain unit. None had missed myocardial infarctions, while three (1%) had cardiac events at six months (all elective revascularisation procedures, with no readmissions with acute coronary syndromes). Another 110 patients (17%) were reclassified as high risk, and 21 (19%) of these had cardiac events (mainly revascularisations) by six months. Patients who were unable to exercise or had non-diagnostic exercise stress test results (equivocal risk) had an intermediate cardiac event rate (8%). CONCLUSIONS: This study validates use of ACPAP. The protocol eliminated missed myocardial infarction; allowed early, safe discharge of low-risk patients; and led to early identification and management of high-risk patients.