Variation in Arterial Access for Invasive Coronary Procedures in New Zealand: A National Analysis (ANZACS-QI 5).

BACKGROUND: Radial arterial access (RA) and femoral arterial access (FA) rates for invasive coronary angiography (ICA) vary widely internationally. The European Society of Cardiology (ESC) suggests default RA is feasible. We aim to investigate the variation in RA rates across all New Zealand public hospitals. METHODS AND RESULTS: Patient characteristics, procedural details, and inpatient outcome data were collected in the All New Zealand Acute Coronary Syndrome - Quality Improvement (ANZACS-QI) registry on consecutive patients undergoing ICA over five months. Of the 5894 ICAs 81% were via RA. Hospitals averaged 25 - 176 procedures/month (46.5% - 96.4% via RA). Operators averaged 17 procedures/month. Those performing more than 20 ICAs/month had RA rates between 61% - 99%. Of the 75 operators, 69% met the ESC recommendation. After multivariable adjustment higher operator (RR 1.12, CI 1.09 - 1.30) and hospital (RR 1.21, CI 1.15 - 1.28) volume were independent predictors of RA. Those with prior CABG (RR 0.51, CI 0.45 - 0.57), STEMI <12h (RR 0.91, CI 0.87 - 0.96), and female sex (RR 0.96, CI 0.94 - 0.99) were less likely to receive RA. CONCLUSIONS: New Zealand has a high RA rate for ICAs. Rates vary substantially between both operators and centres. Radial arterial was highest amongst the highest volume operators and centres.

Activation of KV7 channels stimulates vasodilatation of human placental chorionic plate arteries.

INTRODUCTION: Potassium (K(+)) channels are key regulators of vascular smooth muscle cell (VSMC) excitability. In systemic small arteries, Kv7 channel expression/activity has been noted and a role in vascular tone regulation demonstrated. We aimed to demonstrate functional Kv7 channels in human fetoplacental small arteries. METHODS: Human placental chorionic plate arteries (CPAs) were obtained at term. CPA responses to Kv7 channel modulators was determined by wire myography. Presence of Kv7 channel mRNA (encoded by KCNQ1-5) and protein expression were assessed by RT-PCR and immunohistochemistry/immunofluorescence, respectively. RESULTS: Kv7 channel blockade with linopirdine increased CPA basal tone and AVP-induced contraction. Pre-contracted CPAs (AVP; 80 mM K(+) depolarization solution) exhibited significant relaxation to flupirtine, retigabine, the acrylamide (S)-1, and (S) BMS-204352, differential activators of Kv7.1 - Kv7.5 channels. All CPAs assessed expressed KCNQ1 and KCNQ3-5 mRNA; KCNQ2 was expressed only in a subset of CPAs. Kv7 protein expression was confirmed in intact CPAs and isolated VSMCs. DISCUSSION: Kv7 channels are present and active in fetoplacental vessels, contributing to vascular tone regulation in normal pregnancy. Targeting these channels may represent a therapeutic intervention in pregnancies complicated by increased vascular resistance.

Comparison of the management and in-hospital outcomes of acute coronary syndrome patients in Australia and New Zealand: results from the binational SNAPSHOT acute coronary syndrome 2012 audit.

BACKGROUND/AIMS: We aimed to assess differences in patient management, and outcomes, of Australian and New Zealand patients admitted with a suspected or confirmed acute coronary syndrome (ACS). METHODS: We used comprehensive data from the binational Australia and New Zealand ACS 'SNAPSHOT' audit, acquired on individual patients admitted between 00.00 h on 14 May 2012 to 24.00 h on 27 May 2012. RESULTS: There were 4387 patient admissions, 3381 (77%) in Australia and 1006 (23%) in New Zealand; Australian patients were slightly younger (67 vs 69 years, P = 0.0044). Of the 2356 patients with confirmed ACS, Australian patients were at a lower cardiovascular risk with a lower median Global Registry Acute Coronary Events score (147 vs 154 P = 0.0008), but as likely to receive an invasive coronary angiogram (58% vs 54%, P = 0.082), or revascularisation with percutaneous coronary intervention (32% vs 31%, P = 0.92) or coronary artery bypass graft surgery (7.0% vs 5.6%, P = 0.32). Of the 1937 non-segment elevation myocardial infarction/unstable angina pectoris (NSTEMI/UAP) patients, Australian patients had a shorter time to angiography (46 h vs 67 h, P < 0.0001). However, at discharge, Australian NSTEMI/UAP survivors were less likely to receive aspirin (84% vs 89%, P = 0.0079, a second anti-platelet agent (57% vs 63%, P = 0.050) or a beta blocker (67% vs 77%, P = 0.0002). In-hospital death rates were not different (2.7% vs 3.2%, P = 0.55) between Australia and New Zealand. CONCLUSIONS: Overall more similarities were seen, than differences, in the management of suspected or confirmed ACS patients between Australia and New Zealand. However, in several management areas, both countries could improve the service delivery to this high-risk patient group.

Correlation between Cobb angle, spinous process angle (SPA) and apical vertebrae rotation (AVR) on posteroanterior radiographs in adolescent idiopathic scoliosis (AIS).

PURPOSE: To investigate the accuracy and reliability of the Cobb angle, the spinous process angle (SPA), and apical vertebral rotation (AVR) for measuring adolescent idiopathic scoliosis (AIS), and to evaluate the correlations between these measurements. METHODS: A retrospective study of two sets of standing posteroanterior radiographs of patients with AIS was performed. The first set was 59 consecutive patients with AIS with Cobb angles <45° and the second set was 25 patients with Cobb angles >45°. The Cobb angle, SPA and AVR of each curve was measured twice by three observers with varying measurement experience. The mean absolute difference, standard deviation, and intra- and inter-rater reliability coefficients for each measurement were examined. The Pearson correlation coefficients between any two parameters were reported. The association of the Cobb angle with the SPA and AVR was examined using a multiple regression model. RESULTS: The average intra- and inter-observer reliabilities (ICC [2, 1]) of the Cobb angle, SPA, and AVR were 0.99, 0.95, 0.92 and 0.98, 0.88, 0.83, respectively. The correlation coefficients (r) between Cobb angle and SPA, Cobb angle and AVR, and SPA and AVR were 0.93, 0.68, and 0.60, respectively. Using multiple regression, the association between the Cobb angle and SPA combined with AVR was R (2) = 0.90. The resulting regression model was: [Formula: see text]. CONCLUSION: The SPA has high correlation with the Cobb angle. Including the AVR as an additional factor in multiple regression improves the prediction of the Cobb angle.

Intra- and Interobserver Reliability of the Cobb Angle-Vertebral Rotation Angle-Spinous Process Angle for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A reliability analysis of Cobb angle, vertebral rotation (VR), and spinous process angle (SPA) measurements in adolescent idiopathic scoliosis. OBJECTIVE: To determine the intra- and interobserver reliability of semi-automated digital radiograph measurements. SUMMARY OF BACKGROUND DATA: Cobb angle measurements on posteroanterior radiographs are commonly used to determine the severity of scoliosis. Vertebral rotation helps assess scoliosis 3-dimensionally and has a role in predicting curve progression. Recent studies have shown that the spinous process angle is a useful parameter in assessing scoliosis when using ultrasound imaging. Because the reliability of SPA measurements on radiographs has yet to be determined, it is important to compare the reliability of these 3 parameters (Cobb angle, VR, and SPA) using a computer assisted semi-automated method. METHODS: Sixty posteroanterior radiographs of patients with adolescent idiopathic scoliosis were obtained and measured twice by 3 observers who were blinded to their previous measurements, using an in-house developed program. Measurements were obtained using a semi-automated method to minimize variability resulting from observer reliability. The intra- and interobserver reliabilities were analyzed using intra-class correlation coefficients (ICCs) as well as Bland-Altman's bias and limits of agreement. RESULTS: Over 350 (intra) and 90 (inter) sets of curves with an average Cobb angle of 26° ± 9° (range, 10° to 44°) were compared for each parameter. Intra-observer reliabilities for each parameter were excellent (ICC[2,1], .82; 1.00), with mean absolute differences under 3° between most measurements. Interobserver reliability (ICC[2,1], .72; .95) was mostly good to excellent, with mean absolute differences ranging from 2.0° to 5.6°. CONCLUSIONS: Both the intra- and interobserver assessment of the Cobb, VR, and SPA from the semi-automated measurements had clinically acceptable reliability ranges and may be considered for clinical implementation. Additional studies will be conducted to determine the accuracy and sensitivity to change of these scoliosis severity measurements.

Identification of lead sources in residential environments: Sydney Australia.

Interior and exterior dust, soil and paint were analysed at five brick urban Sydney homes over 15 months to evaluate temporal variations and discriminate sources of lead (Pb) exposure. Exterior dust gauge Pb loading rates (µg/m(2)/28 days), interior vacuum dust Pb concentrations (mg/kg) and interior petri-dish Pb loading rates (µg/m(2)/28 days), were correlated positively with soil Pb concentrations. Exterior dust gauge Pb loading rates and interior vacuum dust Pb concentrations peaked in the summer. Lead isotope and Pb speciation (XAS) were analysed in soil and vacuum dust samples from three of the five houses that had elevated Pb concentrations. Results show that the source of interior dust lead was primarily from soil in two of the three houses and from soil and Pb paint in the third home. IEUBK child blood Pb modelling predicts that children's blood Pb levels could exceed 5 µg/dL in two of the five houses.

Chest pain unit (CPU) in the management of low to intermediate risk acute coronary syndrome: a tertiary hospital experience from New Zealand.

BACKGROUND: A chest pain unit (CPU) for management of patients with chest pain at low to intermediate risk for acute coronary syndrome (ACS) appears safe and cost-effective. We report our experience with a CPU from March 2005 to July 2009. METHODS: Prospective audit of patients presenting with chest pain suggestive of ACS but no high risk features and managed using a CPU, which included; serial cardiac troponins and electrocardiography and exercise tolerance test (ETT) if indicated. Outcomes assessed included three-month readmission rate and one year mortality. RESULTS: 2358 patients were managed according to the CPU. Mean age 56 years (17-96 years), 59% men and median stay of 22h (IQR 17-26h). 1933 (82%) were diagnosed as non-cardiac chest pain. 1741 (74%) patients had an ETT. Median time from triage to ETT was 21h (IQR 16-24h). 64 (2.7%) were readmitted within three months. The majority of readmissions, 39 (61%) were for a non-cardiac cause. Twenty patients (1%) were readmitted with ACS. There was no cardiac death after one year of being discharged as non-cardiac chest pain. CONCLUSIONS: This study confirms that a CPU with high usage of predischarge ETT is a safe and effective way of excluding ACS in patients without high risk features in a New Zealand setting.

Sex-related differences in the presentation, treatment and outcomes among patients with acute coronary syndromes: the Global Registry of Acute Coronary Events.

OBJECTIVE: To assess whether sex differences exist in the angiographic severity, management and outcomes of acute coronary syndromes (ACS). METHODS: The study comprised 7638 women and 19 117 men with ACS who underwent coronary angiography and were included in GRACE (Global Registry of Acute Coronary Events) from 1999-2006. Normal vessels/mild disease was defined as <50% stenosis in all epicardial vessels; advanced disease was defined as >or=one vessel with >or=50% stenosis. RESULTS: Women were older than men and had higher rates of cardiovascular risk factors. Men and women presented equally with chest pain; however, jaw pain and nausea were more frequent among women. Women were more likely to have normal/mild disease (12% vs 6%, p<0.001) and less likely to have left-main and three-vessel disease (27% vs 32%, p<0.001) or undergo percutaneous coronary intervention (65% vs 68%, p<0.001). Women and men with normal and mild disease were treated less aggressively than those with advanced disease. Women with advanced disease had a higher risk of death (4% vs 3%, p<0.01). After adjustment for age and extent of disease, women were more likely to have adverse outcomes (death, myocardial infarction, stroke and rehospitalisation) at six months compared to men (odds ratio 1.24, 95% confidence interval 1.14 to 1.34); however, sex differences in mortality were no longer statistically significant. CONCLUSIONS: Women with ACS were more likely to have cardiovascular disease risk factors and atypical symptoms such as nausea compared with men, but were more likely to have normal/mild angiographic coronary artery disease. Further study regarding sex differences related to disease severity is warranted.

Delay to angiography and outcomes following presentation with high-risk, non-ST-elevation acute coronary syndromes: results from the Global Registry of Acute Coronary Events.

OBJECTIVE: To test if delay-to-angiography (>72 hours from admission) in patients presenting with high-risk non-ST-elevation acute coronary syndromes (NSTE-ACS) is associated with adverse outcomes. DESIGN: GRACE (Global Registry of Acute Coronary Events) is a multinational registry of patients admitted with NSTE-ACS. SETTING: 14 countries with varying healthcare systems. PATIENTS: 23 396 high-risk NSTE-ACS patients with complete initial data collection entered into GRACE between 1999 and 2006 were analysed. INTERVENTIONS: Data were analysed according to delay-to-angiography and subsequent in-hospital or post-discharge adverse outcomes. MAIN OUTCOME MEASURES: Outcomes recorded included death, myocardial infarction, recurrent ischaemia, stroke, new heart failure and composite major adverse cardiovascular event (MACE) comprising death, cerebrovascular accident and myocardial infarction. Revascularisation procedures were recorded. RESULTS: 10 089 (43.1%) had no in-hospital angiography. Median delay-to-angiography was 46 hours; 3680 (34%) patients waited >72 hours. 9.3% waited >7 days before angiography. Patients waiting longest were more often older, diabetic, women and had a history of heart failure, previous myocardial infarction or hypertension. Recurrent in-hospital ischaemia (33% vs 22%), reinfarction (8.4% vs 5.0%) and heart failure (14% vs 9.1%) were more common with delayed angiography. Delayed angiography was associated with better outcomes than no angiography (MACE 18.9% vs 22.2%, p = 0.015). MACE rates within six months of admission were higher with longer delay-to-angiography and highest of all with no angiography. CONCLUSIONS: High-risk NSTE-ACS is suboptimally managed with 43% not undergoing angiography. One-third of those undergoing angiography are delayed >72 hours. Longer delays were more likely with higher risk, sicker patients. These delays were associated with adverse outcomes at six months. Very long delay was associated with lower MACE, but not mortality, compared to conservative management.

NT-pro BNP secretion and clinical endpoints in cardiac surgery intensive care patients.

The primary objective of this study was to determine the pattern of N-Terminal pro brain natriuretic peptide (NT-pro BNP) secretion pre and post cardiac surgery and then to investigate the correlation between levels of serum NT-pro BNP and postoperative clinical and biochemical endpoints. This was a prospective observational study performed at a tertiary centre in New Zealand, examining 118 adult patients undergoing cardiac surgery. Interventions included blood samples for NT-pro BNP and troponin-T taken 48 hours prior to operation and 12, 36 and 72 hours postoperatively. The plasma NT-pro BNP levels increased fourfold postoperatively, to plateau at 36 to 72 hours. Preoperative NT-pro BNP levels correlated with ventilation time (r = 0.46), length of stay in intensive care unit (r = 0.59), total perioperative noradrenaline dose (r = 0.55), but not with postoperative atrial fibrillation or mortality. Using multivariate analysis, serum NT-pro BNP levels at 36 hours were associated with increased noradrenaline dose (P = 0.001), decreased preoperative ejection fraction (EF) Group (P = 0.013) and elevated preoperative NT-pro BNP (P < 0.001). Factors not associated with NT-pro BNP levels at 36 hours include the operation type, bypass and cross-clamp times, use of milrinone and troponin-T We conclude that NT-pro BNP levels increased markedly after cardiac surgery and that high preoperative NT-pro BNP levels are associated with a slow postoperative recovery, but do not predict the occurrence of postoperative atrial fibrillation or mortality. Myocardial ischaemia is an unlikely cause of the NT-pro BNP elevation, because no correlation existed between troponin-T and NT-pro BNP levels.

Implications of hyperglycaemia and ethnicity in patients with acute coronary syndromes in New Zealand.

BACKGROUND: Admission blood glucose (ABG) is an independent predictor of death in patients with acute ST elevation myocardial infarction (STEMI). In New Zealand, mortality following myocardial infarction is disproportionally higher in Maori. Little information, however, exists concerning the predictive value of ABG in non-ST elevation acute coronary syndromes (NSTEACS) events or indeed if similar ethnic differences exist in outcome in this patient population. AIM: To assess the predictive value of ABG and ethnicity in individuals admitted with acute coronary syndromes (ACS) on mortality. METHODS: A retrospective analysis of hospital discharge diagnosis of all ACS between 1 January 1999 and 31 December 2002 at Waikato hospital, Hamilton, New Zealand. The primary outcome was all-cause mortality. RESULTS: There were 4408 episodes of ACS with 1091 (25%) due to STEMI. There were 806 (18%) deaths. The presence of diabetes mellitus (DM) or an elevated ABG, in the absence of a history of DM, was associated with poor patient outcome. Early mortality is seen in individuals presenting with STEMI. People in the highest glucose category were older, more likely to be Maori, had a higher percentage of people with diabetes and remained in hospital longer, regardless of ACS type, than those in the lowest glucose category. Diabetes was more common in Maori (33%) than in Europeans (17.5%); p < 0.001. Significant risk factors for mortality were age, gender, diabetes, ethnicity, glucose and STEMI. For each mmol/l increase in glucose there is a 4.3% increase risk of dying. Adjusting for age and gender, Maori have a much higher mortality than Europeans (RR 2.12; p < 0.00001) regardless of ACS type (STEMI or NSTEACS). CONCLUSIONS: Our study confirms the higher mortality following ACS, of Maori compared to New Zealanders of European origin. A raised ABG is a marker of this increased risk in all patients with ACS.

Management and outcomes of lower risk patients presenting with acute coronary syndromes in a multinational observational registry.

OBJECTIVE: To document patterns of risk stratification, management practices, and outcomes among patients with acute coronary syndromes (ACS) presenting without high risk features. PATIENTS: The study was based on 11,885 consecutive patients presenting with non-ST segment elevation ACS enrolled in GRACE (global registry of acute coronary events). Patients without dynamic ST segment changes, positive troponin (or other cardiac markers), or haemodynamic or arrhythmic instability were defined as being at lower risk. MAIN OUTCOME MEASURES: Management and outcomes were compared with high risk presentations. RESULTS: Of 11,885 patients presenting with unstable angina or non-ST segment elevation myocardial infarction, 4252 (36%) were regarded as being at lower risk. Functional testing for risk stratification was performed in 1163 of 4207 (28%) lower risk and 1531 of 7521 (20%) high risk patients (p < 0.0001). Coronary angiography was performed in 1930 of 4190 (46%) and 3860 of 7544 (51%), and echocardiography in 1692 of 4190 (40%) and 4348 of 7533 (58%) of lower risk and high risk patients, respectively (p < 0.0001 for both). Over one third of patients did not undergo further risk assessment with angiography or functional testing (2746 of 7437 (37%) high risk, 1499 of 4148 (36%) lower risk, not significant). Death occurring in hospital was more likely in the high risk cohort (41 of 4227 (1.0%) lower risk v 215 of 7586 (2.8%) high risk, p < 0.0001), whereas rates of recurrent angina during admission and readmission were similar in both groups (1354 of 4231 (32%) high risk, 2313 of 7587 (31%) lower risk, not significant). In the six months after discharge, death or myocardial infarction occurred in 79 of 3223 (2.5%) lower risk patients and 302 of 5451 (5.5%) high risk patients (p < 0.0001). CONCLUSIONS: Globally, further risk stratification after ACS presentation is suboptimal, regardless of presenting characteristics. Although in-hospital death and myocardial infarction are uncommon, recurrent ischaemia is encountered often in both groups. It remains to be seen whether better outcomes may be achieved with wider application of risk stratification and appropriately directed management strategies.

Cardiac IGF-I manipulation by growth hormone following myocardial infarction.

Evidence of a role for growth hormone (GH) in cardiac structure and function has been derived from studies of patients suffering either GH excess or deficiency, both of which may lead to reduced life expectancy. The role of GH in the ischaemic heart, however, is less than clear. We therefore investigated the effect of 30 days GH treatment in sheep with myocardial infarction. GH treatment significantly increased circulating IGF-I levels (P<0.01), heart weight (P<0.01), and cardiomyocyte cross-sectional area (P<0.001). IGF-I mRNA in peri-infarct cardiac tissue also increased significantly (P<0.05). We conclude that post-infarct GH treatment increases circulating and cardiac IGF-I levels, resulting in significant cardiomyocyte hypertrophy. This increase in cardiomyocyte size appears to correlate with local IGF-I expression rather than plasma IGF-I levels.

Prevention of polymerization of M and Z alpha1-Antitrypsin (alpha1-AT) with trimethylamine N-oxide. Implications for the treatment of alpha1-at deficiency.

alpha1-Antitrypsin (alpha1-AT) is the most abundant circulating proteinase inhibitor. The Z variant results in profound plasma deficiency as the mutant polymerizes within hepatocytes. The retained polymers are associated with cirrhosis, and the lack of circulating protein predisposes to early onset emphysema. We have investigated the role of the naturally occurring solute trimethylamine N-oxide (TMAO) in modulating the polymerization of normal M and disease-associated Z alpha1-AT. TMAO stabilized both M and Z alpha1-AT in an active conformation against heat-induced polymerization. Spectroscopic analysis demonstrated that this was due to inhibition of the conversion of the native state to a polymerogenic intermediate. However, TMAO did not aid the refolding of denatured alpha1-AT to a native conformation; instead, it enhanced polymerization. These data show that TMAO can be used to control the conformational transitions of folded alpha1-AT but that it is ineffective in promoting folding of the polypeptide chain within the secretory pathway.

Osmolytes as modulators of conformational changes in serpins.

Protein misfolding and aggregation play an integral role in many diseases. The misfolding of the serpin (SERine Proteinase INhibitor) alpha1-antitrypsin results in the accumulation of insoluble polymers within hepatocytes and alpha1-antitrypsin deficiency in plasma, predisposing patients to liver cirrhosis and emphysema. We have examined the effect of three naturally occurring osmolytes, sarcosine, glycine betaine and trimethylamine N-oxide, on conformational changes in alpha1-antitrypsin. All three solutes protected native alpha1-antitrypsin against thermally induced polymerisation and inactivation in a concentration-dependent manner. Further spectroscopic analysis showed that sarcosine stabilises the native conformation of alpha1-antitrypsin, thus hindering its conversion to an intermediate state and subsequent polymerisation. On refolding in the presence of sarcosine, alpha1-antitrypsin formed a heterogeneous population, with increasing proportions of molecules adopting an inactive conformation in higher concentrations of the osmolyte. These data show that sarcosine can be used to prevent abnormal structural changes in native alpha1-antitrypsin, but is ineffective in facilitating the correct folding of the protein. The implications of these results in the context of conformational changes and states adopted by alpha1-antitrypsin are discussed.

A randomized study of direct coronary stent delivery compared with stenting after predilatation: the NIR future trial. On behalf of the NIR Future Trial Investigators.

This randomized trial compared a strategy of direct stenting without predilatation (n = 39) with conventional stenting with predilatation (n = 42) in patients with suitable lesions in native vessels > or = 2. 5-mm diameter to be covered by either a 9- or 16-mm-length NIR Primo stent. Equipment cost [mean (median) +/- SD] was less in those with direct stenting [$1,199 (979) +/- 526] than in those with predilatation [$1,455 (1,285) +/- 401, P < 0.001]. There was no significant difference in contrast use or fluoroscopy time. Procedural time was shorter in the direct stenting group. The clinical outcome at 1 month was satisfactory in both groups. In selected patients, a strategy of direct stenting is feasible, costs less, and is quicker to perform than the conventional strategy of stenting following predilatation.

An ovine model of chronic stable heart failure.

BACKGROUND: Chronic stable large animal models of heart failure are difficult to establish. We report an ovine model of chronic stable heart failure achieved by a technique of repetitive myocardial infarctions (one of the most common causes of cardiac failure) with catheter-based techniques. METHODS AND RESULTS: Ejection fraction (EF) was assessed by echocardiography. A perfusion catheter was positioned in either the left anterior descending or circumflex artery by using standard angioplasty techniques. Myocardial infarction was induced by a Gelfoam embolism via this catheter and was confirmed by electrocardiographic (ECG) changes and new segmental abnormalities. The procedure was repeated at 2 weekly intervals until the EF was less than 40%. Target EF was achieved in 15 animals, with a mean of 3.4 embolizations (range 2 to 8). Baseline EF was 68%, with a mean final EF of 33%. This resulted in a 54% reduction in EF (range 44% to 68%) from baseline values. Two animals developed late symptomatic heart failure and died, whereas EF was stable at 3-month follow-up echocardiography in the remaining animals with no significant spontaneous improvement. CONCLUSION: Chronic stable heart failure can be established in sheep with catheter-based skills and a microembolization technique that causes repetitive myocardial infarctions.

The impact of coronary stenting on immediate procedural complication and long-term clinical restenosis at Waikato Hospital.

AIM: Clinical data on coronary stenting from within New Zealand is scarce and, in particular, the impact of current stent technologies is unknown. We reviewed all angioplasties undertaken at Waikato Hospital over a two year period to determine the clinical effect of coronary stenting on the local population. METHODS: Data from all patients who underwent coronary angioplasty at Waikato Hospital between July 1, 1995 and July 1, 1997 were included. Stents were deployed either to remedy sub-optimal results, or were electively used for saphenous vein grafts or restenotic lesions. Patient follow-up was obtained through a combination of database review, chart search and GP or patient contact. RESULTS: 662 lesions were dilated in 441 patients. 91 lesions were stented, 52.7% for sub-optimal results following balloon angioplasty. 98% of patients were followed up at six months. Whilst procedural success rate was higher in stented patients compared to unstented patients (96.7% vs 87.5% respectively, p=0.009) the in-hospital sub-acute occlusion rate was also increased (6.8% vs 1.9% respectively, p=0.007). At six months, coronary restenosis requiring repeat angioplasty was infrequent (10.9% overall) with no significant difference between the two groups (8.1% vs. 11.2% for stented vs unstented patients respectively, p=NS). CONCLUSIONS: The use of stents appears effective in improving immediate procedural success rates. Despite stented patients being at higher risk initially, their complication and six month clinical restenosis rates were similar.