primary angioplasty and thrombolytic therapy have both been recommended as appropriate reperfusion therapies for patients presenting with either st - segment elevation or new - onset left bundle branch block , within 12 h of the onset of ischaemic symptoms . certain caveats apply to the recommendations for primary angioplasty , including the prior experience of the operator ( who must perform at least 75 procedures per year ) and the throughput of the centre ( which must perform at least 200 procedures per year ) . the procedure must also be performed in a timely fashion , ie balloon dilation must occur within 60 to 90 min of the diagnosis of acute mi . the evidence for thrombolytic therapy is based on randomised comparisons with placebo or control treatment in over 100,000 patients . the evidence for primary angioplasty is based on comparisons with thrombolytic therapy in a total of 2745 patients , of whom 1348 underwent primary angioplasty . 75 years , whereas the recent systematic overview of primary angioplasty trials included data from only 199 patients aged  75 years , 149 of whom underwent primary angioplasty . the ftt overview did not specifically report the outcomes of elderly patients presenting with st - segment elevation or bundle branch block within 12 h of symptom onset , and did not include data on gender or infarct site . it did , however , include all patients randomised up to 24 h after symptom onset , regardless of electrocardiographic findings ( eg normal electrocardiograms , t - wave inversion , st - segment depression , etc ) . in the 5788 patients  75 years of age presenting with any electrocardiographic changes within 24 h of symptom onset , thrombolytic therapy reduced mortality nonsignificantly from 25.3% to 24.3% ( 95% confidence interval -16 to 36 ) . new data from the ftt collaborative group show that in patients over 75 presenting with st - segment elevation or bundle branch block within 12 h of symptom onset , thrombolytic therapy reduced the mortality rate significantly by 15% ( from 29.4% with control treatment to 26.0% , p = 0.03 ) . this represents 34 lives saved per 1000 patients treated , twice the benefit seen in patients aged < 55 years ( 16 lives saved per 1000 treated ) ( personal communication from the ftt secretariat , dated 4 august 2000 ) . these results can be generalised to community hospitals as the bulk of the data in the ftt overview came from the second international study of infarct survival ( isis-2 ) and gruppo italiano per lo studio della streptochinasi nell'infarto miocardico ( gissi-1 ) trials , which were conducted predominantly in non - academic centres . unlike primary angioplasty , thrombolytic therapy requires no specialised skills . in a study of 516 united states ( us ) hospitals , there was no significant association between the volume of thrombolytic treatments given and in - hospital mortality , whereas the in - hospital mortality rates associated with primary angioplasty were 28% lower in high - volume centres ( > 33 procedures / year ) than in low - volume centres ( 5 to 11 procedures / year ) . several registry studies   have recently concluded that thrombolytic therapy worsens outcomes in the elderly . in a us medicare observational study , the 30-day mortality rates among 7864 patients aged between 76 and 86 years presenting within 4 h of symptom onset were 15.4% with thrombolytic therapy and 18% with control treatment ( p = 0.003 ) . the authors concluded that thrombolytic therapy was ' unlikely to confer survival benefit and may have significant disadvantage ' . it should be noted , however , that a large proportion of the patients given thrombolytic therapy had contraindications , for example 12% had a systolic blood pressure of > 180 mmhg , and 18% had a recent history of trauma , peptic ulcer or internal bleeding . the cooperative cardiovascular project , which studied 16,305 patients considered ' ideal ' for reperfusion therapy , reported that 30-day mortality rates were reduced by primary angioplasty , but not by thrombolytic therapy . at 1 year , however , both treatment modalities were associated with lower mortality rates than control treatment ( odds ratios for mortality 0.85 [ 95% confidence interval 0.77 to 0.94 ] with thrombolytic therapy and 0.63 [ 95% confidence interval 0.49 to 0.81 ] with primary angioplasty , after adjustment for baseline characteristics ) . patients who received thrombolytic therapy within 30 min had lower mortality rates at both 30 days and 1 year than those who received it later . in patients over 65 , the mean time to thrombolytic therapy was 62  48 min and the mean time to primary angioplasty was 131  60 min . only 42% of eligible patients with no absolute contraindications against thrombolytic therapy received reperfusion therapy ( 4.2% underwent primary angioplasty ) . although adjustments were made for known variables in both of these studies , observational studies can sometimes be confounded by the influence of unforeseen factors . for this reason , randomised trial data are usually considered more reliable because randomisation helps to ensure that unforeseen factors are balanced between the different treatment groups . it is inappropriate to rely upon registry data as a basis for clinical management , as illustrated by various large registry studies that have subsequently been shown to be wrong . in most instances the relative benefits of treatment are similar across different risk groups , unless there is an a priori reason why a particular subgroup should differ in its response to treatment . following mi the elderly have a much higher mortality rate and a higher incidence of complications such as heart failure and cardiogenic shock . they are also more prone to the haemorrhagic complications of thrombolytic therapy , such as intracranial haemorrhage , and one would therefore expect primary angioplasty to have its greatest benefit in the elderly . there are , however , few data specifically concerning primary angioplasty in the elderly . in the primary angioplasty in myocardial infarction ( pami ) study , which compared angioplasty with the older 3-h tissue plasminogen activator ( tpa ) infusion regimen , the greatest benefit was observed in patients over 65 . there was no significant reduction in the combined endpoint of death / mi in patients under 65 ( 0.8% mortality in both groups ) , but there was a marked reduction in the same endpoint in patients  65 ( death / mi was 8.6% with angioplasty versus 20.0% with tpa , p = 0.048 ) . in the global use of strategies to open occluded coronary arteries ( gusto)-iib trial , the largest randomised trial comparing angioplasty with thrombolytic therapy , 1138 patients were randomised to receive either accelerated tpa or primary angioplasty . although primary angioplasty resulted in better 30-day outcomes ( death / mi / stroke occurred in 9.6% versus 13.7% with tpa , p = 0.03 ) , there was no significant difference in death / mi at 6 months ( 13.3% versus 15.0% , respectively , odds ratio 0.87 [ 95% confidence interval 0.62 to 1.23 ] ) . while the absolute benefit of angioplasty was greater with each decade of life , the relative benefit was no greater in older than in younger patients . although the numbers were small ( n = 90 ) there was no difference in mortality for patients  80 years ( 27.3% with angioplasty versus 26.7% with tpa ) . likewise , a recent systematic overview of all trials comparing primary angioplasty with thrombolytic therapy reported that there was no difference in the relative benefit in the elderly , although the absolute benefit was greater . why are n't the advantages of angioplasty over thrombolytic therapy greater in the elderly than in younger patients ? one reason is that elderly patients tend to delay longer before presenting for treatment , thus reducing the window of opportunity for myocardial salvage . this is particularly disadvantageous in patients treated with primary angioplasty , who already face a longer wait for reperfusion once they arrive at hospital , compared with those treated with thrombolytic therapy , which can be initiated sooner . the elderly also tend to have more severe coronary stenoses and greater impairment of thrombolysis in myocardial infarction ( timi ) grade 3 flow at baseline . in gusto - iib , for instance , timi grade 3 flow was present in 19% of patients aged < 40 versus 6% of those aged 70 to 79 . there is evidence that thrombolytic therapy lyses coronary artery thrombi just as well in the elderly as it does in younger patients . in the gusto - i angiographic sub - study , univariate and multivariate analysis showed that age was not a predictor of timi flow grades at 90 min , with similar proportions of patients under and over the age of 75 achieving timi grade 3 flow ( 38% versus 37% ) . although the elderly are more prone to bleeding ( particularly intracranial haemorrhage ) following thrombolytic therapy , most patients suffering intracranial haemorrhage die ( 60% in gusto - i ) rather than survive with a disability ( 20% in gusto - i ) , and so the benefit : risk ratio of thrombolytic therapy is largely already accounted for in the mortality statistics . the recent systematic overview of all trials comparing primary angioplasty with thrombolytic therapy   showed that the mortality benefits were maintained at 6 months , but with borderline statistical significance ( p = 0.04 ) . some of the trials had missing data , and if one extra death had occurred in the angioplasty limb of one of these trials , or if two studies had reported equal outcomes , there would have been no significant overall mortality advantage associated with primary angioplasty . in this overview , there was a trend showing that longer door - to - balloon times tended to be associated with lesser benefits of primary angioplasty . in the recent stent - pami study , the mean door - to - balloon time was 112 min . some researchers have suggested that the time to treatment may be less important with primary angioplasty than with thrombolytic therapy . the scientific rationale for this is uncertain as myocardial salvage is clearly time - dependent , and patency of the infarct - related artery has other long - term advantages that are independent of salvage , such as decreased left ventricular remodelling , improved electrical stability , and the capacity for collateral supply to other coronary territories in the event of reinfarction . although thrombolytic therapy is less effective at lysing old clots , patency does improve with time . in gusto - i , for instance , streptokinase achieved patency ( timi grade 2 or 3 ) in 57% of patients by 90 min and 73% by 180 min , while accelerated tpa achieved patency in 76% by 180 min . in the second us national registry of myocardial infarction , 27,080 patients were treated with primary angioplasty between june 1994 and march 1998 , and it was found that the mortality rate was significantly related to the door - to - balloon time ( median 116 min ) . the adjusted mortality rates were 41% higher in patients with door - balloon times of > 2 h and 62% higher in those with door - to - balloon times of > 3 h ( p < 0.001 ) . it should be noted that the timing of angioplasty was not randomised in these studies . the quest for more effective pharmacological reperfusion strategies must be balanced against the risk of increasing intracranial haemorrhage rates . the percentage of patients suffering intracranial haemorrhage has risen with the introduction of the newer thrombolytic agents , partly because more elderly patients are now being included in clinical trials , and possibly also because the ability to detect haemorrhagic complications has improved . however , the increase in intracranial haemorrhage can not be entirely explained by changing demographics . tenecteplase is a new , relatively fibrin - specific bolus thrombolytic agent . in the second assessment of the safety and efficacy of a new thrombolytic ( assent-2 ) trial , the rates of major bleeding ( ie life - threatening , resulting in death or requiring transfusion ) in the over-75 age group were 8.12% with tenecteplase and 11.62% with tpa . the rates of intracranial haemorrhage in the same age group were 1.72% and 2.62% , respectively . these results suggest that tenecteplase may be particularly suitable for use in the elderly , as may newer thrombolytic regimens incorporating either a half - dose thrombolytic plus a iib / iiia inhibitor or a full - dose thrombolytic plus the direct thrombin inhibitor , bivalirudin , which have been shown to cause less bleeding than unfractionated heparin . angioplasty with stenting has been shown to achieve timi grade 3 flow in a very high proportion of patients , for example 86% in stent - pami . the trial registry showed that of the 1458 patients with acute mi who were screened , only 900 ( 62% ) were randomised . the reasons why angioplasty is sometimes not performed include poor vascular access , renal failure and other comorbid conditions . if a ' rule of ninety - fives ' is applied to all patients with acute mi who are eligible for reperfusion ( ie 95% of patients are eligible for angioplasty  stenting , 95% of these procedures are successful , and 95% of patients whose procedures are successful achieve timi grade 3 flow ) , then the actual incidence of timi grade 3 flow for all comers is 86% ( ie 95%  95%  95% ) . this incidence of timi grade 3 flow is no better than that achieved with half - dose tpa plus abciximab in the timi-14 trial . it is also important to remember that in the real world , primary angioplasty takes considerably longer to perform than thrombolysis . the interventionist performing the procedure may well be less experienced than those participating in clinical trials , which tend to be conducted in centres of excellence . the patency rates achieved by primary angioplasty in the real world may therefore be nearer those seen with thrombolytic therapy than those achieved under optimal clinical trial conditions . it is likely that advances in adjunctive therapies will enhance the reperfusion rates achieved by both approaches , and hence patient outcomes should also improve . primary angioplasty has its greatest benefit in high - risk patients and in the elderly , for whom thrombolysis carries an increased risk of stroke ( particularly haemorrhagic stroke ) . although there is potential to develop chest pain units where patients with acute mi could be triaged for transfer to centres of excellence with expertise in angioplasty , the costs and logistical difficulties of such an approach would be considerable . only about 25% of hospitals in the us have the capacity to perform angioplasty , and so it is unlikely that this procedure will be readily available to the majority of patients presenting with acute mi in the near future . prompt administration of a thrombolytic regimen , with facilitated angioplasty reserved for patients identified as high - risk ( such as the elderly and patients with evidence of reperfusion failure ) , is likely to result in the greatest good for the greatest number of patients . regardless of the reperfusion strategy used , event rates in the elderly remain high , and so further research is needed to develop better treatments . meanwhile , it is vital that as many patients as possible receive reperfusion therapy as soon as possible by whichever means is available .
thrombolysis and primary angioplasty are both recommended reperfusion strategies for elderly patients presenting with myocardial infarction ( mi ) . 
 primary angioplasty is most beneficial in high - risk patients . 
 while the elderly have a high absolute risk of dying or developing complications after mi , they also have an increased risk of intracranial haemorrhage if they are given thrombolytic therapy . 
 it could therefore be reasonably argued that primary angioplasty is the reperfusion strategy of choice in the elderly . 
 however , primary angioplasty has not been shown to have a greater relative benefit than thrombolytic therapy in the elderly . 
 recent data from the fibrinolytic therapy trialists ' ( ftt ) collaborative group show that thrombolytic therapy significantly reduces mortality compared with control treatment in patients over 75 years of age presenting within 12 h of symptom onset , with st - segment elevation or bundle branch block . 
 future advances in adjunctive therapies may improve myocyte perfusion and hence the outcomes achieved by both invasive and noninvasive reperfusion strategies . 
 better thrombolytic regimens incorporating adjunctive agents such as bivalirudin may reduce the risk of intracranial haemorrhage . 
 few hospitals can provide a 24-h primary angioplasty service with door - to - balloon times consistently less than 90 min , and thrombolytic therapy is therefore a far more practical option in most instances .